Refs #4059 Work in progress: Conversion to use Namespaces of dozen more classes

Removed many Piwik_ functions, in Piwik 2 it is best practise to use the methods calls instead

Todo: finish converting core/ classes + convert plugins/ classes to use \Piwik\Plugin namespace + fix build + Merge master

129 files changed, 906 insertions, 646 deletions

diff --git a/plugins/API/API.php b/plugins/API/API.php
index e85974fd8e..74c7c011de 100644
--- a/plugins/API/API.php
+++ b/plugins/API/API.php
@@ -8,6 +8,8 @@
  * @category Piwik_Plugins
  * @package Piwik_API
  */
+use Piwik\API\Request;
+use Piwik\API\Proxy;
 use Piwik\DataTable\Filter\ColumnDelete;
 use Piwik\DataTable\Row;
 use Piwik\Metrics;
@@ -16,6 +18,7 @@ use Piwik\Common;
 use Piwik\Config;
 use Piwik\Date;
 use Piwik\DataTable;
+use Piwik\Version;
 use Piwik\Plugin;
 use Piwik\Translate;
 
@@ -105,7 +108,7 @@ class Piwik_API_API
     public function getPiwikVersion()
     {
         Piwik::checkUserHasSomeViewAccess();
-        return Piwik_Version::VERSION;
+        return Version::VERSION;
     }
 
     /**
@@ -143,7 +146,7 @@ class Piwik_API_API
             'segment'        => 'visitIp',
             'acceptedValues' => '13.54.122.1, etc.',
             'sqlSegment'     => 'log_visit.location_ip',
-            'sqlFilter'      => array('Piwik_IP', 'P2N'),
+            'sqlFilter'      => array('IP', 'P2N'),
             'permission'     => $isAuthenticatedWithViewAccess,
         );
         $segments[] = array(
@@ -470,7 +473,7 @@ class Piwik_API_API
             // load the data
             $className = 'Piwik_' . $plugin . '_API';
             $params['columns'] = implode(',', $columns);
-            $dataTable = Piwik_API_Proxy::getInstance()->call($className, 'get', $params);
+            $dataTable = Proxy::getInstance()->call($className, 'get', $params);
             // make sure the table has all columns
             $array = ($dataTable instanceof DataTable\Map ? $dataTable->getArray() : array($dataTable));
             foreach ($array as $table) {
@@ -567,7 +570,7 @@ class Piwik_API_API
 
         $result = array();
         foreach ($urls as $url) {
-            $req = new Piwik_API_Request($url . '&format=php&serialize=0');
+            $req = new Request($url . '&format=php&serialize=0');
             $result[] = $req->process();
         }
         return $result;
@@ -618,7 +621,7 @@ class Piwik_API_API
             $requestLastVisits .= "&filter_limit=1000";
         }
 
-        $request = new Piwik_API_Request($requestLastVisits);
+        $request = new Request($requestLastVisits);
         $table = $request->process();
         if (empty($table)) {
             throw new Exception("There was no data to suggest for $segmentName");
diff --git a/plugins/API/Controller.php b/plugins/API/Controller.php
index 16d8f9dd1f..ed4addae2c 100644
--- a/plugins/API/Controller.php
+++ b/plugins/API/Controller.php
@@ -8,14 +8,19 @@
  * @category Piwik_Plugins
  * @package Piwik_API
  */
+use Piwik\API\DocumentationGenerator;
+use Piwik\API\Request;
+use Piwik\API\Proxy;
 use Piwik\Config;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\View;
 
 /**
  *
  * @package Piwik_API
  */
-class Piwik_API_Controller extends Piwik_Controller
+class Piwik_API_Controller extends Controller
 {
     function index()
     {
@@ -23,23 +28,23 @@ class Piwik_API_Controller extends Piwik_Controller
         if (!isset($_GET['filter_limit'])) {
             $_GET['filter_limit'] = Config::getInstance()->General['API_datatable_default_limit'];
         }
-        $request = new Piwik_API_Request('token_auth=' . Common::getRequestVar('token_auth', 'anonymous', 'string'));
+        $request = new Request('token_auth=' . Common::getRequestVar('token_auth', 'anonymous', 'string'));
         echo $request->process();
     }
 
     public function listAllMethods()
     {
-        $ApiDocumentation = new Piwik_API_DocumentationGenerator();
+        $ApiDocumentation = new DocumentationGenerator();
         echo $ApiDocumentation->getAllInterfaceString($outputExampleUrls = true, $prefixUrls = Common::getRequestVar('prefixUrl', ''));
     }
 
     public function listAllAPI()
     {
-        $view = new Piwik_View("@API/listAllAPI");
+        $view = new View("@API/listAllAPI");
         $this->setGeneralVariablesView($view);
 
-        $ApiDocumentation = new Piwik_API_DocumentationGenerator();
-        $view->countLoadedAPI = Piwik_API_Proxy::getInstance()->getCountRegisteredClasses();
+        $ApiDocumentation = new DocumentationGenerator();
+        $view->countLoadedAPI = Proxy::getInstance()->getCountRegisteredClasses();
         $view->list_api_methods_with_links = $ApiDocumentation->getAllInterfaceString();
         echo $view->render();
     }
diff --git a/plugins/API/ProcessedReport.php b/plugins/API/ProcessedReport.php
index a008c82025..b30a3d7901 100644
--- a/plugins/API/ProcessedReport.php
+++ b/plugins/API/ProcessedReport.php
@@ -1,4 +1,5 @@
 <?php
+use Piwik\API\Request;
 use Piwik\DataTable\Simple;
 use Piwik\DataTable\Row;
 use Piwik\Metrics;
@@ -7,6 +8,8 @@ use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Date;
 use Piwik\DataTable;
+use Piwik\Url;
+use Piwik\Timer;
 use Piwik\Site;
 
 /**
@@ -243,7 +246,7 @@ class Piwik_API_ProcessedReport
                                        $apiParameters = false, $idGoal = false, $language = false,
                                        $showTimer = true, $hideMetricsDoc = false, $idSubtable = false, $showRawMetrics = false)
     {
-        $timer = new Piwik_Timer();
+        $timer = new Timer();
         if (empty($apiParameters)) {
             $apiParameters = array();
         }
@@ -273,8 +276,8 @@ class Piwik_API_ProcessedReport
                                                   ));
         if (!empty($segment)) $parameters['segment'] = $segment;
 
-        $url = Piwik_Url::getQueryStringFromParameters($parameters);
-        $request = new Piwik_API_Request($url);
+        $url = Url::getQueryStringFromParameters($parameters);
+        $request = new Request($url);
         try {
             /** @var DataTable */
             $dataTable = $request->process();
diff --git a/plugins/API/RowEvolution.php b/plugins/API/RowEvolution.php
index ec6b3c06fc..21ab108c8d 100644
--- a/plugins/API/RowEvolution.php
+++ b/plugins/API/RowEvolution.php
@@ -8,6 +8,9 @@
  * @category Piwik_Plugins
  * @package Piwik_API
  */
+use Piwik\API\DataTableManipulator\LabelFilter;
+use Piwik\API\ResponseBuilder;
+use Piwik\API\Request;
 use Piwik\DataTable\Filter\CalculateEvolutionFilter;
 use Piwik\DataTable\Filter\SafeDecodeLabel;
 use Piwik\DataTable\Row;
@@ -15,6 +18,7 @@ use Piwik\Period;
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\DataTable;
+use Piwik\Url;
 
 /**
  * This class generates a Row evolution dataset, from input request
@@ -36,7 +40,7 @@ class Piwik_API_RowEvolution
             throw new Exception("Row evolutions can not be processed with this combination of \'date\' and \'period\' parameters.");
         }
 
-        $label = Piwik_API_ResponseBuilder::unsanitizeLabelParameter($label);
+        $label = ResponseBuilder::unsanitizeLabelParameter($label);
         $labels = Piwik::getArrayFromApiParameter($label);
 
 
@@ -80,7 +84,7 @@ class Piwik_API_RowEvolution
             foreach ($table->getRows() as $row) {
                 $label = $row->getColumn('label');
                 if (isset($labelsToIndex[$label])) {
-                    $row->setMetadata(Piwik_API_DataTableManipulator_LabelFilter::FLAG_IS_ROW_EVOLUTION, $labelsToIndex[$label]);
+                    $row->setMetadata(LabelFilter::FLAG_IS_ROW_EVOLUTION, $labelsToIndex[$label]);
                 }
             }
         }
@@ -155,7 +159,7 @@ class Piwik_API_RowEvolution
 
         // if we have a recursive label and no url, use the path
         if (!$urlFound) {
-            $actualLabel = str_replace(Piwik_API_DataTableManipulator_LabelFilter::SEPARATOR_RECURSIVE_LABEL, ' - ', $label);
+            $actualLabel = str_replace(LabelFilter::SEPARATOR_RECURSIVE_LABEL, ' - ', $label);
         }
 
         $return = array(
@@ -237,9 +241,9 @@ class Piwik_API_RowEvolution
             $parameters['filter_add_columns_when_show_all_columns'] = '1';
         }
 
-        $url = Piwik_Url::getQueryStringFromParameters($parameters);
+        $url = Url::getQueryStringFromParameters($parameters);
 
-        $request = new Piwik_API_Request($url);
+        $request = new Request($url);
 
         try {
             $dataTable = $request->process();
@@ -450,7 +454,7 @@ class Piwik_API_RowEvolution
     }
 
     /**
-     * Returns the row in a datatable by its Piwik_API_DataTableManipulator_LabelFilter::FLAG_IS_ROW_EVOLUTION metadata.
+     * Returns the row in a datatable by its LabelFilter::FLAG_IS_ROW_EVOLUTION metadata.
      *
      * @param DataTable $table
      * @param int $labelIdx
@@ -461,7 +465,7 @@ class Piwik_API_RowEvolution
         $labelIdx = (int)$labelIdx;
         foreach ($table->getRows() as $row)
         {
-            if ($row->getMetadata(Piwik_API_DataTableManipulator_LabelFilter::FLAG_IS_ROW_EVOLUTION) === $labelIdx)
+            if ($row->getMetadata(LabelFilter::FLAG_IS_ROW_EVOLUTION) === $labelIdx)
             {
                 return $row;
             }
@@ -476,6 +480,6 @@ class Piwik_API_RowEvolution
      */
     private function cleanOriginalLabel($label)
     {
-        return str_replace(Piwik_API_DataTableManipulator_LabelFilter::SEPARATOR_RECURSIVE_LABEL, ' - ', $label);
+        return str_replace(LabelFilter::SEPARATOR_RECURSIVE_LABEL, ' - ', $label);
     }
 }
diff --git a/plugins/Actions/Actions.php b/plugins/Actions/Actions.php
index 0906c0cbd3..f333277c03 100644
--- a/plugins/Actions/Actions.php
+++ b/plugins/Actions/Actions.php
@@ -8,9 +8,11 @@
  * @category Piwik_Plugins
  * @package Piwik_Actions
  */
+use Piwik\API\Request;
 use Piwik\ArchiveProcessor;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\ViewDataTable;
 use Piwik\Plugin;
 use Piwik\SegmentExpression;
 use Piwik\Site;
@@ -156,7 +158,7 @@ class Piwik_Actions extends Plugin
         ) {
             $sql = Piwik_Tracker_Action::getSqlSelectActionId();
             $bind = array($valueToMatch, $valueToMatch, $actionType);
-            $idAction = Piwik_FetchOne($sql, $bind);
+            $idAction = Db::fetchOne($sql, $bind);
             // if the action is not found, we hack -100 to ensure it tries to match against an integer
             // otherwise binding idaction_name to "false" returns some rows for some reasons (in case &segment=pageTitle==Větrnásssssss)
             if (empty($idAction)) {
@@ -523,24 +525,24 @@ class Piwik_Actions extends Plugin
 
     function addWidgets()
     {
-        Piwik_AddWidget('Actions_Actions', 'Actions_SubmenuPages', 'Actions', 'getPageUrls');
-        Piwik_AddWidget('Actions_Actions', 'Actions_WidgetPageTitles', 'Actions', 'getPageTitles');
-        Piwik_AddWidget('Actions_Actions', 'Actions_SubmenuOutlinks', 'Actions', 'getOutlinks');
-        Piwik_AddWidget('Actions_Actions', 'Actions_SubmenuDownloads', 'Actions', 'getDownloads');
-        Piwik_AddWidget('Actions_Actions', 'Actions_WidgetPagesEntry', 'Actions', 'getEntryPageUrls');
-        Piwik_AddWidget('Actions_Actions', 'Actions_WidgetPagesExit', 'Actions', 'getExitPageUrls');
-        Piwik_AddWidget('Actions_Actions', 'Actions_WidgetEntryPageTitles', 'Actions', 'getEntryPageTitles');
-        Piwik_AddWidget('Actions_Actions', 'Actions_WidgetExitPageTitles', 'Actions', 'getExitPageTitles');
+        WidgetsList::add('Actions_Actions', 'Actions_SubmenuPages', 'Actions', 'getPageUrls');
+        WidgetsList::add('Actions_Actions', 'Actions_WidgetPageTitles', 'Actions', 'getPageTitles');
+        WidgetsList::add('Actions_Actions', 'Actions_SubmenuOutlinks', 'Actions', 'getOutlinks');
+        WidgetsList::add('Actions_Actions', 'Actions_SubmenuDownloads', 'Actions', 'getDownloads');
+        WidgetsList::add('Actions_Actions', 'Actions_WidgetPagesEntry', 'Actions', 'getEntryPageUrls');
+        WidgetsList::add('Actions_Actions', 'Actions_WidgetPagesExit', 'Actions', 'getExitPageUrls');
+        WidgetsList::add('Actions_Actions', 'Actions_WidgetEntryPageTitles', 'Actions', 'getEntryPageTitles');
+        WidgetsList::add('Actions_Actions', 'Actions_WidgetExitPageTitles', 'Actions', 'getExitPageTitles');
 
         if ($this->isSiteSearchEnabled()) {
-            Piwik_AddWidget('Actions_SubmenuSitesearch', 'Actions_WidgetSearchKeywords', 'Actions', 'getSiteSearchKeywords');
+            WidgetsList::add('Actions_SubmenuSitesearch', 'Actions_WidgetSearchKeywords', 'Actions', 'getSiteSearchKeywords');
 
             if (self::isCustomVariablesPluginsEnabled()) {
-                Piwik_AddWidget('Actions_SubmenuSitesearch', 'Actions_WidgetSearchCategories', 'Actions', 'getSiteSearchCategories');
+                WidgetsList::add('Actions_SubmenuSitesearch', 'Actions_WidgetSearchCategories', 'Actions', 'getSiteSearchCategories');
             }
-            Piwik_AddWidget('Actions_SubmenuSitesearch', 'Actions_WidgetSearchNoResultKeywords', 'Actions', 'getSiteSearchNoResultKeywords');
-            Piwik_AddWidget('Actions_SubmenuSitesearch', 'Actions_WidgetPageUrlsFollowingSearch', 'Actions', 'getPageUrlsFollowingSiteSearch');
-            Piwik_AddWidget('Actions_SubmenuSitesearch', 'Actions_WidgetPageTitlesFollowingSearch', 'Actions', 'getPageTitlesFollowingSiteSearch');
+            WidgetsList::add('Actions_SubmenuSitesearch', 'Actions_WidgetSearchNoResultKeywords', 'Actions', 'getSiteSearchNoResultKeywords');
+            WidgetsList::add('Actions_SubmenuSitesearch', 'Actions_WidgetPageUrlsFollowingSearch', 'Actions', 'getPageUrlsFollowingSiteSearch');
+            WidgetsList::add('Actions_SubmenuSitesearch', 'Actions_WidgetPageTitlesFollowingSearch', 'Actions', 'getPageTitlesFollowingSiteSearch');
         }
     }
 
@@ -660,7 +662,7 @@ class Piwik_Actions extends Plugin
         // so users can see that they can set it to 1 (see #3365)
         $result['custom_parameters'] = array('flat' => 0);
         
-        if (Piwik_ViewDataTable::shouldLoadExpanded()) {
+        if (ViewDataTable::shouldLoadExpanded()) {
             $result['show_expanded'] = true;
             
             $result['filters'][] = function ($dataTable) {
@@ -764,7 +766,7 @@ class Piwik_Actions extends Plugin
     {
         // link to the page, not just the report, but only if not a widget
         $widget = Common::getRequestVar('widget', false);
-        $reportUrl = Piwik_API_Request::getCurrentUrlWithoutGenericFilters(array(
+        $reportUrl = Request::getCurrentUrlWithoutGenericFilters(array(
             'module' => 'Actions',
             'action' => $widget === false ? 'indexEntryPageUrls' : 'getEntryPageUrls'
         ));
@@ -793,7 +795,7 @@ class Piwik_Actions extends Plugin
     {
         // link to the page, not just the report, but only if not a widget
         $widget = Common::getRequestVar('widget', false);
-        $reportUrl = Piwik_API_Request::getCurrentUrlWithoutGenericFilters(array(
+        $reportUrl = Request::getCurrentUrlWithoutGenericFilters(array(
             'module' => 'Actions',
             'action' => $widget === false ? 'indexExitPageUrls' : 'getExitPageUrls'
         ));
@@ -901,7 +903,7 @@ class Piwik_Actions extends Plugin
     {
         // link to the page, not just the report, but only if not a widget
         $widget = Common::getRequestVar('widget', false);
-        $reportUrl = Piwik_API_Request::getCurrentUrlWithoutGenericFilters(array(
+        $reportUrl = Request::getCurrentUrlWithoutGenericFilters(array(
             'module' => 'Actions',
             'action' => $widget === false ? 'indexPageTitles' : 'getPageTitles'
         ));
diff --git a/plugins/Actions/Archiver.php b/plugins/Actions/Archiver.php
index 987bf5104a..dc6242dd95 100644
--- a/plugins/Actions/Archiver.php
+++ b/plugins/Actions/Archiver.php
@@ -13,6 +13,7 @@ use Piwik\DataTable\Manager;
 use Piwik\DataTable\Row\DataTableSummaryRow;
 use Piwik\Metrics;
 use Piwik\DataTable;
+use Piwik\RankingQuery;
 use Piwik\PluginsArchiver;
 
 /**
@@ -215,7 +216,7 @@ class Piwik_Actions_Archiver extends PluginsArchiver
 
         $rankingQuery = false;
         if ($rankingQueryLimit > 0) {
-            $rankingQuery = new Piwik_RankingQuery($rankingQueryLimit);
+            $rankingQuery = new RankingQuery($rankingQueryLimit);
             $rankingQuery->setOthersLabel(DataTable::LABEL_SUMMARY_ROW);
             $rankingQuery->addLabelColumn(array('idaction', 'name'));
             $rankingQuery->addColumn(array('url_prefix', Metrics::INDEX_NB_UNIQ_VISITORS));
@@ -294,7 +295,7 @@ class Piwik_Actions_Archiver extends PluginsArchiver
     {
         $rankingQuery = false;
         if ($rankingQueryLimit > 0) {
-            $rankingQuery = new Piwik_RankingQuery($rankingQueryLimit);
+            $rankingQuery = new RankingQuery($rankingQueryLimit);
             $rankingQuery->setOthersLabel(DataTable::LABEL_SUMMARY_ROW);
             $rankingQuery->addLabelColumn('idaction');
             $rankingQuery->addColumn(Metrics::INDEX_PAGE_ENTRY_NB_UNIQ_VISITORS);
@@ -345,7 +346,7 @@ class Piwik_Actions_Archiver extends PluginsArchiver
     {
         $rankingQuery = false;
         if ($rankingQueryLimit > 0) {
-            $rankingQuery = new Piwik_RankingQuery($rankingQueryLimit);
+            $rankingQuery = new RankingQuery($rankingQueryLimit);
             $rankingQuery->setOthersLabel(DataTable::LABEL_SUMMARY_ROW);
             $rankingQuery->addLabelColumn('idaction');
             $rankingQuery->addColumn(Metrics::INDEX_PAGE_EXIT_NB_UNIQ_VISITORS);
@@ -391,7 +392,7 @@ class Piwik_Actions_Archiver extends PluginsArchiver
     {
         $rankingQuery = false;
         if ($rankingQueryLimit > 0) {
-            $rankingQuery = new Piwik_RankingQuery($rankingQueryLimit);
+            $rankingQuery = new RankingQuery($rankingQueryLimit);
             $rankingQuery->setOthersLabel(DataTable::LABEL_SUMMARY_ROW);
             $rankingQuery->addLabelColumn('idaction');
             $rankingQuery->addColumn(Metrics::INDEX_PAGE_SUM_TIME_SPENT, 'sum');
diff --git a/plugins/Actions/Controller.php b/plugins/Actions/Controller.php
index f90ad12f28..36002fe2de 100644
--- a/plugins/Actions/Controller.php
+++ b/plugins/Actions/Controller.php
@@ -8,13 +8,16 @@
  * @category Piwik_Plugins
  * @package Piwik_Actions
  */
+use Piwik\Controller;
+use Piwik\ViewDataTable;
+use Piwik\View;
 
 /**
  * Actions controller
  *
  * @package Piwik_Actions
  */
-class Piwik_Actions_Controller extends Piwik_Controller
+class Piwik_Actions_Controller extends Controller
 {
     // 
     // Actions that render whole pages
@@ -22,28 +25,28 @@ class Piwik_Actions_Controller extends Piwik_Controller
     
     public function indexPageUrls($fetch = false)
     {
-        return Piwik_View::singleReport(
+        return View::singleReport(
             Piwik_Translate('Actions_SubmenuPages'),
             $this->getPageUrls(true), $fetch);
     }
 
     public function indexEntryPageUrls($fetch = false)
     {
-        return Piwik_View::singleReport(
+        return View::singleReport(
             Piwik_Translate('Actions_SubmenuPagesEntry'),
             $this->getEntryPageUrls(true), $fetch);
     }
 
     public function indexExitPageUrls($fetch = false)
     {
-        return Piwik_View::singleReport(
+        return View::singleReport(
             Piwik_Translate('Actions_SubmenuPagesExit'),
             $this->getExitPageUrls(true), $fetch);
     }
 
     public function indexSiteSearch()
     {
-        $view = new Piwik_View('@Actions/indexSiteSearch');
+        $view = new View('@Actions/indexSiteSearch');
 
         $view->keywords = $this->getSiteSearchKeywords(true);
         $view->noResultKeywords = $this->getSiteSearchNoResultKeywords(true);
@@ -59,21 +62,21 @@ class Piwik_Actions_Controller extends Piwik_Controller
 
     public function indexPageTitles($fetch = false)
     {
-        return Piwik_View::singleReport(
+        return View::singleReport(
             Piwik_Translate('Actions_SubmenuPageTitles'),
             $this->getPageTitles(true), $fetch);
     }
 
     public function indexDownloads($fetch = false)
     {
-        return Piwik_View::singleReport(
+        return View::singleReport(
             Piwik_Translate('Actions_SubmenuDownloads'),
             $this->getDownloads(true), $fetch);
     }
 
     public function indexOutlinks($fetch = false)
     {
-        return Piwik_View::singleReport(
+        return View::singleReport(
             Piwik_Translate('Actions_SubmenuOutlinks'),
             $this->getOutlinks(true), $fetch);
     }
@@ -84,66 +87,66 @@ class Piwik_Actions_Controller extends Piwik_Controller
     
     public function getPageUrls($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
     
     public function getEntryPageUrls($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getExitPageUrls($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getSiteSearchKeywords($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getSiteSearchNoResultKeywords($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getSiteSearchCategories($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getPageUrlsFollowingSiteSearch($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getPageTitlesFollowingSiteSearch($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getPageTitles($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getEntryPageTitles($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getExitPageTitles($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getDownloads($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getOutlinks($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 }
diff --git a/plugins/Annotations/Controller.php b/plugins/Annotations/Controller.php
index f632ab5ae8..739ec5deeb 100755
--- a/plugins/Annotations/Controller.php
+++ b/plugins/Annotations/Controller.php
@@ -8,14 +8,17 @@
  * @category Piwik_Plugins
  * @package Piwik_Annotations
  */
+use Piwik\API\Request;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\View;
 
 /**
  * Controller for the Annotations plugin.
  *
  * @package Piwik_Annotations
  */
-class Piwik_Annotations_Controller extends Piwik_Controller
+class Piwik_Annotations_Controller extends Controller
 {
     /**
      * Controller action that returns HTML displaying annotations for a site and
@@ -56,9 +59,9 @@ class Piwik_Annotations_Controller extends Piwik_Controller
         }
 
         // create & render the view
-        $view = new Piwik_View('@Annotations/getAnnotationManager');
+        $view = new View('@Annotations/getAnnotationManager');
 
-        $allAnnotations = Piwik_API_Request::processRequest(
+        $allAnnotations = Request::processRequest(
             'Annotations.getAll', array('date' => $date, 'period' => $period, 'lastN' => $lastN));
         $view->annotations = empty($allAnnotations[$idSite]) ? array() : $allAnnotations[$idSite];
 
@@ -104,11 +107,11 @@ class Piwik_Annotations_Controller extends Piwik_Controller
         if ($_SERVER["REQUEST_METHOD"] == "POST") {
             $this->checkTokenInUrl();
 
-            $view = new Piwik_View('@Annotations/saveAnnotation');
+            $view = new View('@Annotations/saveAnnotation');
 
             // NOTE: permissions checked in API method
             // save the annotation
-            $view->annotation = Piwik_API_Request::processRequest("Annotations.save");
+            $view->annotation = Request::processRequest("Annotations.save");
 
             echo $view->render();
         }
@@ -147,7 +150,7 @@ class Piwik_Annotations_Controller extends Piwik_Controller
             }
 
             // add the annotation. NOTE: permissions checked in API method
-            Piwik_API_Request::processRequest("Annotations.add", array('date' => $date));
+            Request::processRequest("Annotations.add", array('date' => $date));
 
             $managerDate = Common::getRequestVar('managerDate', false);
             $managerPeriod = Common::getRequestVar('managerPeriod', false);
@@ -178,7 +181,7 @@ class Piwik_Annotations_Controller extends Piwik_Controller
             $this->checkTokenInUrl();
 
             // delete annotation. NOTE: permissions checked in API method
-            Piwik_API_Request::processRequest("Annotations.delete");
+            Request::processRequest("Annotations.delete");
 
             echo $this->getAnnotationManager($fetch = true);
         }
@@ -205,11 +208,11 @@ class Piwik_Annotations_Controller extends Piwik_Controller
     public function getEvolutionIcons()
     {
         // get annotation the count
-        $annotationCounts = Piwik_API_Request::processRequest(
+        $annotationCounts = Request::processRequest(
             "Annotations.getAnnotationCountForDates", array('getAnnotationText' => 1));
 
         // create & render the view
-        $view = new Piwik_View('@Annotations/getEvolutionIcons');
+        $view = new View('@Annotations/getEvolutionIcons');
         $view->annotationCounts = reset($annotationCounts); // only one idSite allowed for this action
 
         echo $view->render();
diff --git a/plugins/AnonymizeIP/AnonymizeIP.php b/plugins/AnonymizeIP/AnonymizeIP.php
index 7d6ce520a9..79af7308a5 100644
--- a/plugins/AnonymizeIP/AnonymizeIP.php
+++ b/plugins/AnonymizeIP/AnonymizeIP.php
@@ -10,6 +10,7 @@
  */
 use Piwik\Config;
 use Piwik\Common;
+use Piwik\Version;
 use Piwik\Plugin;
 
 /**
@@ -28,7 +29,7 @@ class Piwik_AnonymizeIP extends Plugin
             'description'     => Piwik_Translate('AnonymizeIP_PluginDescription'),
             'author'          => 'Piwik',
             'author_homepage' => 'http://piwik.org/',
-            'version'         => Piwik_Version::VERSION,
+            'version'         => Version::VERSION,
         );
     }
 
diff --git a/plugins/CoreAdminHome/API.php b/plugins/CoreAdminHome/API.php
index fe6772fe09..6877d8ac90 100644
--- a/plugins/CoreAdminHome/API.php
+++ b/plugins/CoreAdminHome/API.php
@@ -15,6 +15,7 @@ use Piwik\Piwik;
 use Piwik\Config;
 use Piwik\Common;
 use Piwik\Date;
+use Piwik\TaskScheduler;
 use Piwik\Site;
 
 /**
@@ -43,7 +44,7 @@ class Piwik_CoreAdminHome_API
     public function runScheduledTasks()
     {
         Piwik::checkUserIsSuperUser();
-        return Piwik_TaskScheduler::runTasks();
+        return TaskScheduler::runTasks();
     }
 
     public function getKnownSegmentsToArchive()
@@ -173,7 +174,7 @@ class Piwik_CoreAdminHome_API
             $query = "DELETE FROM $table " .
                 " WHERE ( $sql ) " .
                 " AND idsite IN (" . $sqlIdSites . ")";
-            Piwik_Query($query, $bind);
+            Db::query($query, $bind);
         }
 
         // Update piwik_site.ts_created
@@ -183,7 +184,7 @@ class Piwik_CoreAdminHome_API
 					AND ts_created > ?";
         $minDateSql = $minDate->subDay(1)->getDatetime();
         $bind = array($minDateSql, $minDateSql);
-        Piwik_Query($query, $bind);
+        Db::query($query, $bind);
 
         // Force to re-process data for these websites in the next archive.php cron run
         $invalidatedIdSites = Piwik_CoreAdminHome_API::getWebsiteIdsToInvalidate();
diff --git a/plugins/CoreAdminHome/Controller.php b/plugins/CoreAdminHome/Controller.php
index 5bae81c756..7ccf51921e 100644
--- a/plugins/CoreAdminHome/Controller.php
+++ b/plugins/CoreAdminHome/Controller.php
@@ -8,17 +8,22 @@
  * @category Piwik_Plugins
  * @package Piwik_CoreAdminHome
  */
+use Piwik\API\ResponseBuilder;
 use Piwik\ArchiveProcessor\Rules;
 use Piwik\Config;
+use Piwik\Controller\Admin;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Nonce;
+use Piwik\View;
+use Piwik\Url;
 use Piwik\Site;
 
 /**
  *
  * @package Piwik_CoreAdminHome
  */
-class Piwik_CoreAdminHome_Controller extends Piwik_Controller_Admin
+class Piwik_CoreAdminHome_Controller extends Admin
 {
     const LOGO_HEIGHT = 300;
     const LOGO_SMALL_HEIGHT = 100;
@@ -31,7 +36,7 @@ class Piwik_CoreAdminHome_Controller extends Piwik_Controller_Admin
     public function generalSettings()
     {
         Piwik::checkUserHasSomeAdminAccess();
-        $view = new Piwik_View('@CoreAdminHome/generalSettings');
+        $view = new View('@CoreAdminHome/generalSettings');
 
         if (Piwik::isUserIsSuperUser()) {
             $enableBrowserTriggerArchiving = Rules::isBrowserTriggerEnabled();
@@ -78,7 +83,7 @@ class Piwik_CoreAdminHome_Controller extends Piwik_Controller_Admin
     public function setGeneralSettings()
     {
         Piwik::checkUserIsSuperUser();
-        $response = new Piwik_API_ResponseBuilder(Common::getRequestVar('format'));
+        $response = new ResponseBuilder(Common::getRequestVar('format'));
         try {
             $this->checkTokenInUrl();
             $enableBrowserTriggerArchiving = Common::getRequestVar('enableBrowserTriggerArchiving');
@@ -112,7 +117,7 @@ class Piwik_CoreAdminHome_Controller extends Piwik_Controller_Admin
             // update trusted host settings
             $trustedHosts = Common::getRequestVar('trustedHosts', false, 'json');
             if ($trustedHosts !== false) {
-                Piwik_Url::saveTrustedHostnameInConfig($trustedHosts);
+                Url::saveTrustedHostnameInConfig($trustedHosts);
             }
 
             $config->forceSave();
@@ -130,7 +135,7 @@ class Piwik_CoreAdminHome_Controller extends Piwik_Controller_Admin
      */
     public function trackingCodeGenerator()
     {
-        $view = new Piwik_View('@CoreAdminHome/trackingCodeGenerator');
+        $view = new View('@CoreAdminHome/trackingCodeGenerator');
         $this->setBasicVariablesView($view);
         $view->topMenu = Piwik_GetTopMenu();
 
@@ -170,15 +175,15 @@ class Piwik_CoreAdminHome_Controller extends Piwik_Controller_Admin
 
         $nonce = Common::getRequestVar('nonce', false);
         $language = Common::getRequestVar('language', '');
-        if ($nonce !== false && Piwik_Nonce::verifyNonce('Piwik_OptOut', $nonce)) {
-            Piwik_Nonce::discardNonce('Piwik_OptOut');
+        if ($nonce !== false && Nonce::verifyNonce('Piwik_OptOut', $nonce)) {
+            Nonce::discardNonce('Piwik_OptOut');
             Piwik_Tracker_IgnoreCookie::setIgnoreCookie();
             $trackVisits = !$trackVisits;
         }
 
-        $view = new Piwik_View('@CoreAdminHome/optOut');
+        $view = new View('@CoreAdminHome/optOut');
         $view->trackVisits = $trackVisits;
-        $view->nonce = Piwik_Nonce::getNonce('Piwik_OptOut', 3600);
+        $view->nonce = Nonce::getNonce('Piwik_OptOut', 3600);
         $view->language = Piwik_LanguagesManager_API::getInstance()->isLanguageAvailable($language)
             ? $language
             : Piwik_LanguagesManager::getLanguageCodeForCurrentUser();
diff --git a/plugins/CoreAdminHome/CoreAdminHome.php b/plugins/CoreAdminHome/CoreAdminHome.php
index 39a4f08199..8b4aece240 100644
--- a/plugins/CoreAdminHome/CoreAdminHome.php
+++ b/plugins/CoreAdminHome/CoreAdminHome.php
@@ -12,6 +12,7 @@ use Piwik\DataAccess\ArchiveSelector;
 use Piwik\DataAccess\ArchiveTableCreator;
 use Piwik\Piwik;
 use Piwik\Date;
+use Piwik\ScheduledTask;
 use Piwik\Plugin;
 
 /**
@@ -36,19 +37,19 @@ class Piwik_CoreAdminHome extends Plugin
     public function getScheduledTasks(&$tasks)
     {
         // general data purge on older archive tables, executed daily
-        $purgeArchiveTablesTask = new Piwik_ScheduledTask ($this,
+        $purgeArchiveTablesTask = new ScheduledTask ($this,
             'purgeOutdatedArchives',
             null,
             new Piwik_ScheduledTime_Daily(),
-            Piwik_ScheduledTask::HIGH_PRIORITY);
+            ScheduledTask::HIGH_PRIORITY);
         $tasks[] = $purgeArchiveTablesTask;
 
         // lowest priority since tables should be optimized after they are modified
-        $optimizeArchiveTableTask = new Piwik_ScheduledTask ($this,
+        $optimizeArchiveTableTask = new ScheduledTask ($this,
             'optimizeArchiveTable',
             null,
             new Piwik_ScheduledTime_Daily(),
-            Piwik_ScheduledTask::LOWEST_PRIORITY);
+            ScheduledTask::LOWEST_PRIORITY);
         $tasks[] = $optimizeArchiveTableTask;
     }
 
@@ -104,6 +105,6 @@ class Piwik_CoreAdminHome extends Plugin
     function optimizeArchiveTable()
     {
         $archiveTables = ArchiveTableCreator::getTablesArchivesInstalled();
-        Piwik_OptimizeTables($archiveTables);
+        Db::optimizeTables($archiveTables);
     }
 }
diff --git a/plugins/CoreHome/Controller.php b/plugins/CoreHome/Controller.php
index c95b5d61ce..8d52088cae 100644
--- a/plugins/CoreHome/Controller.php
+++ b/plugins/CoreHome/Controller.php
@@ -8,16 +8,23 @@
  * @category Piwik_Plugins
  * @package Piwik_CoreHome
  */
+use Piwik\API\Request;
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Date;
+use Piwik\AssetManager;
+use Piwik\Controller;
+use Piwik\FrontController;
+use Piwik\View;
+use Piwik\Url;
+use Piwik\UpdateCheck;
 use Piwik\Site;
 
 /**
  *
  * @package Piwik_CoreHome
  */
-class Piwik_CoreHome_Controller extends Piwik_Controller
+class Piwik_CoreHome_Controller extends Controller
 {
     function getDefaultAction()
     {
@@ -52,13 +59,13 @@ class Piwik_CoreHome_Controller extends Piwik_Controller
             throw new Exception("Preventing infinite recursion...");
         }
         $view = $this->getDefaultIndexView();
-        $view->content = Piwik_FrontController::getInstance()->fetchDispatch($controllerName, $actionName);
+        $view->content = FrontController::getInstance()->fetchDispatch($controllerName, $actionName);
         echo $view->render();
     }
 
     protected function getDefaultIndexView()
     {
-        $view = new Piwik_View('@CoreHome/getDefaultIndexView');
+        $view = new View('@CoreHome/getDefaultIndexView');
         $this->setGeneralVariablesView($view);
         $view->menu = Piwik_GetMenu();
         $view->content = '';
@@ -104,7 +111,7 @@ class Piwik_CoreHome_Controller extends Piwik_Controller
      */
     public function getCss()
     {
-        $cssMergedFile = Piwik_AssetManager::getMergedCssFileLocation();
+        $cssMergedFile = AssetManager::getMergedCssFileLocation();
         Piwik::serveStaticFile($cssMergedFile, "text/css");
     }
 
@@ -116,7 +123,7 @@ class Piwik_CoreHome_Controller extends Piwik_Controller
      */
     public function getJs()
     {
-        $jsMergedFile = Piwik_AssetManager::getMergedJsFileLocation();
+        $jsMergedFile = AssetManager::getMergedJsFileLocation();
         Piwik::serveStaticFile($jsMergedFile, "application/javascript; charset=UTF-8");
     }
 
@@ -140,7 +147,7 @@ class Piwik_CoreHome_Controller extends Piwik_Controller
     {
         $rowEvolution = $this->makeRowEvolution($isMulti = false);
         self::$rowEvolutionCache = $rowEvolution;
-        $view = new Piwik_View('@CoreHome/getRowEvolutionPopover');
+        $view = new View('@CoreHome/getRowEvolutionPopover');
         echo $rowEvolution->renderPopover($this, $view);
     }
 
@@ -149,7 +156,7 @@ class Piwik_CoreHome_Controller extends Piwik_Controller
     {
         $rowEvolution = $this->makeRowEvolution($isMulti = true);
         self::$rowEvolutionCache = $rowEvolution;
-        $view = new Piwik_View('@CoreHome/getMultiRowEvolutionPopover');
+        $view = new View('@CoreHome/getMultiRowEvolutionPopover');
         echo $rowEvolution->renderPopover($this, $view);
     }
 
@@ -191,9 +198,9 @@ class Piwik_CoreHome_Controller extends Piwik_Controller
         $this->checkTokenInUrl();
 
         // perform check (but only once every 10s)
-        Piwik_UpdateCheck::check($force = false, Piwik_UpdateCheck::UI_CLICK_CHECK_INTERVAL);
+        UpdateCheck::check($force = false, UpdateCheck::UI_CLICK_CHECK_INTERVAL);
 
-        $view = new Piwik_View('@CoreHome/checkForUpdates');
+        $view = new View('@CoreHome/checkForUpdates');
         $this->setGeneralVariablesView($view);
         echo $view->render();
     }
@@ -203,7 +210,7 @@ class Piwik_CoreHome_Controller extends Piwik_Controller
      */
     public function getDonateForm()
     {
-        $view = new Piwik_View('@CoreHome/getDonateForm');
+        $view = new View('@CoreHome/getDonateForm');
         if (Common::getRequestVar('widget', false)
             && Piwik::isUserIsSuperUser()
         ) {
@@ -217,7 +224,7 @@ class Piwik_CoreHome_Controller extends Piwik_Controller
      */
     public function getPromoVideo()
     {
-        $view = new Piwik_View('@CoreHome/getPromoVideo');
+        $view = new View('@CoreHome/getPromoVideo');
         $view->shareText = Piwik_Translate('CoreHome_SharePiwikShort');
         $view->shareTextLong = Piwik_Translate('CoreHome_SharePiwikLong');
         $view->promoVideoUrl = 'http://www.youtube.com/watch?v=OslfF_EH81g';
@@ -229,7 +236,7 @@ class Piwik_CoreHome_Controller extends Piwik_Controller
      */
     public function redirectToPaypal()
     {
-        $parameters = Piwik_API_Request::getRequestArrayFromString($request = null);
+        $parameters = Request::getRequestArrayFromString($request = null);
         foreach ($parameters as $name => $param) {
             if ($name == 'idSite'
                 || $name == 'module'
@@ -239,7 +246,7 @@ class Piwik_CoreHome_Controller extends Piwik_Controller
             }
         }
         
-        $url = "https://www.paypal.com/cgi-bin/webscr?".Piwik_Url::getQueryStringFromParameters($parameters);
+        $url = "https://www.paypal.com/cgi-bin/webscr?".Url::getQueryStringFromParameters($parameters);
         
         header("Location: $url");
         exit;
diff --git a/plugins/CoreHome/CoreHome.php b/plugins/CoreHome/CoreHome.php
index 56c4dbbfd2..d568007482 100644
--- a/plugins/CoreHome/CoreHome.php
+++ b/plugins/CoreHome/CoreHome.php
@@ -33,8 +33,8 @@ class Piwik_CoreHome extends Plugin
      */
     public function addWidgets()
     {
-        Piwik_AddWidget('Example Widgets', 'CoreHome_SupportPiwik', 'CoreHome', 'getDonateForm');
-        Piwik_AddWidget('Example Widgets', 'Installation_Welcome', 'CoreHome', 'getPromoVideo');
+        WidgetsList::add('Example Widgets', 'CoreHome_SupportPiwik', 'CoreHome', 'getDonateForm');
+        WidgetsList::add('Example Widgets', 'Installation_Welcome', 'CoreHome', 'getPromoVideo');
     }
 
     public function getCssFiles(&$cssFiles)
diff --git a/plugins/CoreHome/DataTableRowAction/MultiRowEvolution.php b/plugins/CoreHome/DataTableRowAction/MultiRowEvolution.php
index e8625a2e07..bbfc80832f 100644
--- a/plugins/CoreHome/DataTableRowAction/MultiRowEvolution.php
+++ b/plugins/CoreHome/DataTableRowAction/MultiRowEvolution.php
@@ -9,6 +9,7 @@
  * @package Piwik_CoreHome
  */
 use Piwik\Common;
+use Piwik\ViewDataTable;
 
 /**
  * MULTI ROW EVOLUTION
@@ -76,7 +77,7 @@ class Piwik_CoreHome_DataTableRowAction_MultiRowEvolution
      * Generic method to get an evolution graph or a sparkline for the row evolution popover.
      * Do as much as possible from outside the controller.
      *
-     * @return Piwik_ViewDataTable
+     * @return ViewDataTable
      */
     public function getRowEvolutionGraph()
     {
diff --git a/plugins/CoreHome/DataTableRowAction/RowEvolution.php b/plugins/CoreHome/DataTableRowAction/RowEvolution.php
index 3b3bea686c..694a64c641 100644
--- a/plugins/CoreHome/DataTableRowAction/RowEvolution.php
+++ b/plugins/CoreHome/DataTableRowAction/RowEvolution.php
@@ -8,9 +8,13 @@
  * @category Piwik_Plugins
  * @package Piwik_CoreHome
  */
+use Piwik\API\ResponseBuilder;
+use Piwik\API\Request;
 use Piwik\Common;
 use Piwik\Metrics;
 use Piwik\Date;
+use Piwik\ViewDataTable;
+use Piwik\Url;
 
 /**
  * ROW EVOLUTION
@@ -78,7 +82,7 @@ class Piwik_CoreHome_DataTableRowAction_RowEvolution
         $this->apiMethod = Common::getRequestVar('apiMethod', '', 'string');
         if (empty($this->apiMethod)) throw new Exception("Parameter apiMethod not set.");
 
-        $this->label = Piwik_API_ResponseBuilder::getLabelFromRequest($_GET);
+        $this->label = ResponseBuilder::getLabelFromRequest($_GET);
         $this->label = $this->label[0];
 
         if ($this->label === '') throw new Exception("Parameter label not set.");
@@ -95,7 +99,7 @@ class Piwik_CoreHome_DataTableRowAction_RowEvolution
             list($this->date, $lastN) =
                 Piwik_ViewDataTable_GenerateGraphHTML_ChartEvolution::getDateRangeAndLastN($this->period, $end);
         }
-        $this->segment = Piwik_ViewDataTable::getRawSegmentFromRequest();
+        $this->segment = ViewDataTable::getRawSegmentFromRequest();
 
         $this->loadEvolutionReport();
     }
@@ -154,9 +158,9 @@ class Piwik_CoreHome_DataTableRowAction_RowEvolution
             $parameters['column'] = $column;
         }
 
-        $url = Piwik_Url::getQueryStringFromParameters($parameters);
+        $url = Url::getQueryStringFromParameters($parameters);
 
-        $request = new Piwik_API_Request($url);
+        $request = new Request($url);
         $report = $request->process();
 
         $this->extractEvolutionReport($report);
@@ -174,12 +178,12 @@ class Piwik_CoreHome_DataTableRowAction_RowEvolution
     /**
      * Generic method to get an evolution graph or a sparkline for the row evolution popover.
      * Do as much as possible from outside the controller.
-     * @return Piwik_ViewDataTable
+     * @return ViewDataTable
      */
     public function getRowEvolutionGraph()
     {
         // set up the view data table
-        $view = Piwik_ViewDataTable::factory($this->graphType);
+        $view = ViewDataTable::factory($this->graphType);
         $view->setDataTable($this->dataTable);
         $view->init('CoreHome', 'getRowEvolutionGraph', $this->apiMethod);
 
diff --git a/plugins/CoreHome/javascripts/datatable_rowactions.js b/plugins/CoreHome/javascripts/datatable_rowactions.js
index 5aea12e4b1..233fa34683 100644
--- a/plugins/CoreHome/javascripts/datatable_rowactions.js
+++ b/plugins/CoreHome/javascripts/datatable_rowactions.js
@@ -164,7 +164,7 @@ DataTable_RowAction.prototype.trigger = function (tr, e, subTableLabel) {
     label = label.trim();
     // if we have received the event from the sub table, add the label
     if (subTableLabel) {
-        var separator = ' > '; // Piwik_API_DataTableManipulator_LabelFilter::SEPARATOR_RECURSIVE_LABEL
+        var separator = ' > '; // LabelFilter::SEPARATOR_RECURSIVE_LABEL
         label += separator + subTableLabel.trim();
     }
 
diff --git a/plugins/CoreHome/templates/_siteSelect.twig b/plugins/CoreHome/templates/_siteSelect.twig
index 80d337828b..e78b93b0bd 100644
--- a/plugins/CoreHome/templates/_siteSelect.twig
+++ b/plugins/CoreHome/templates/_siteSelect.twig
@@ -4,14 +4,14 @@
  * - allSitesItemText The text to use for the 'All Websites' option. Default = 'All Websites'.
  * - allWebsitesLinkLocation The location of the 'All Websites' option. Can be 'top' or 'bottom'. Default = 'bottom'.
  * - showSelectedSite false if the currently selected site should be excluded from the list of sites. Default = false.
- * - sites The list of sites to use. By default, the first N sites are used. They are retrieved in Piwik_View.
+ * - sites The list of sites to use. By default, the first N sites are used. They are retrieved in View.
  * - show_autocompleter Whether to show the autocompleter or not. Default true.
  * - switchSiteOnSelect Whether to change the page w/ a new idSite value when a site is selected, or not.
  *                      Default = true.
  * - inputName If set, a hidden <input> w/ name == $inputName is created which will hold the selected site's ID. For
  *             use with <form> elements.
- * - siteName The currently selected site name. Defaults to the first name in $sites set by Piwik_View.
- * - idSite The currently selected idSite. Defaults to the first id in $sites set by Piwik_View.
+ * - siteName The currently selected site name. Defaults to the first name in $sites set by View.
+ * - idSite The currently selected idSite. Defaults to the first id in $sites set by View.
  #}
 {% set sitesSelector_allWebsitesLink %}
     <div class="custom_select_all" style="clear: both">
diff --git a/plugins/CorePluginsAdmin/Controller.php b/plugins/CorePluginsAdmin/Controller.php
index ff0900073e..c1156cce99 100644
--- a/plugins/CorePluginsAdmin/Controller.php
+++ b/plugins/CorePluginsAdmin/Controller.php
@@ -8,15 +8,18 @@
  * @category Piwik_Plugins
  * @package Piwik_CorePluginsAdmin
  */
+use Piwik\Controller\Admin;
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Config;
+use Piwik\View;
+use Piwik\Url;
 
 /**
  *
  * @package Piwik_CorePluginsAdmin
  */
-class Piwik_CorePluginsAdmin_Controller extends Piwik_Controller_Admin
+class Piwik_CorePluginsAdmin_Controller extends Admin
 {
     function extend()
     {
@@ -41,7 +44,7 @@ class Piwik_CorePluginsAdmin_Controller extends Piwik_Controller_Admin
     protected function configureView($template)
     {
         Piwik::checkUserIsSuperUser();
-        $view = new Piwik_View($template);
+        $view = new View($template);
         $this->setBasicVariablesView($view);
         $this->displayWarningIfConfigFileNotWritable($view);
         return $view;
@@ -115,7 +118,7 @@ class Piwik_CorePluginsAdmin_Controller extends Piwik_Controller_Admin
     protected function redirectAfterModification($redirectAfter)
     {
         if ($redirectAfter) {
-            Piwik_Url::redirectToReferer();
+            Url::redirectToReferer();
         }
     }
 
diff --git a/plugins/CoreUpdater/Controller.php b/plugins/CoreUpdater/Controller.php
index 11e0c9c7d1..8d427b9813 100644
--- a/plugins/CoreUpdater/Controller.php
+++ b/plugins/CoreUpdater/Controller.php
@@ -8,16 +8,24 @@
  * @category Piwik_Plugins
  * @package Piwik_CoreUpdater
  */
+use Piwik\API\Request;
 use Piwik\ArchiveProcessor\Rules;
 use Piwik\Config;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\Http;
+use Piwik\Piwik_Updater;
+use Piwik\View;
+use Piwik\Version;
+use Piwik\UpdateCheck;
+use Piwik\Unzip;
 
 /**
  *
  * @package Piwik_CoreUpdater
  */
-class Piwik_CoreUpdater_Controller extends Piwik_Controller
+class Piwik_CoreUpdater_Controller extends Controller
 {
     const CONFIG_FILE_BACKUP = '/config/global.ini.auto-backup-before-update.php';
     const PATH_TO_EXTRACT_LATEST_VERSION = '/tmp/latest/';
@@ -41,8 +49,8 @@ class Piwik_CoreUpdater_Controller extends Piwik_Controller
 
         $newVersion = $this->checkNewVersionIsAvailableOrDie();
 
-        $view = new Piwik_View('@CoreUpdater/newVersionAvailable');
-        $view->piwik_version = Piwik_Version::VERSION;
+        $view = new View('@CoreUpdater/newVersionAvailable');
+        $view->piwik_version = Version::VERSION;
         $view->piwik_new_version = $newVersion;
         $view->piwik_latest_version_url = self::getLatestZipUrl($newVersion);
         $view->can_auto_update = Piwik::canAutoUpdate();
@@ -90,10 +98,10 @@ class Piwik_CoreUpdater_Controller extends Piwik_Controller
 
     public function oneClickResults()
     {
-        Piwik_API_Request::reloadAuthUsingTokenAuth($_POST);
+        Request::reloadAuthUsingTokenAuth($_POST);
         Piwik::checkUserIsSuperUser();
 
-        $view = new Piwik_View('@CoreUpdater/oneClickResults');
+        $view = new View('@CoreUpdater/oneClickResults');
         $view->coreError = Common::getRequestVar('error', '', 'string', $_POST);
         $view->feedbackMessages = safe_unserialize(Common::unsanitizeInputValue(Common::getRequestVar('messages', '', 'string', $_POST)));
         echo $view->render();
@@ -101,9 +109,9 @@ class Piwik_CoreUpdater_Controller extends Piwik_Controller
 
     private function checkNewVersionIsAvailableOrDie()
     {
-        $newVersion = Piwik_UpdateCheck::isNewestVersionAvailable();
+        $newVersion = UpdateCheck::isNewestVersionAvailable();
         if (!$newVersion) {
-            throw new Exception(Piwik_TranslateException('CoreUpdater_ExceptionAlreadyLatestVersion', Piwik_Version::VERSION));
+            throw new Exception(Piwik_TranslateException('CoreUpdater_ExceptionAlreadyLatestVersion', Version::VERSION));
         }
         return $newVersion;
     }
@@ -115,7 +123,7 @@ class Piwik_CoreUpdater_Controller extends Piwik_Controller
 
         // we catch exceptions in the caller (i.e., oneClickUpdate)
         $url = self::getLatestZipUrl($this->newVersion) . '?cb=' . $this->newVersion;
-        $fetched = Piwik_Http::fetchRemoteFile($url, $this->pathPiwikZip);
+        $fetched = Http::fetchRemoteFile($url, $this->pathPiwikZip);
     }
 
     private function oneClick_Unpack()
@@ -127,7 +135,7 @@ class Piwik_CoreUpdater_Controller extends Piwik_Controller
             Piwik::unlinkRecursive($this->pathRootExtractedPiwik, true);
         }
 
-        $archive = Piwik_Unzip::factory('PclZip', $this->pathPiwikZip);
+        $archive = Unzip::factory('PclZip', $this->pathPiwikZip);
 
         if (0 == ($archive_files = $archive->extract($pathExtracted))) {
             throw new Exception(Piwik_TranslateException('CoreUpdater_ExceptionArchiveIncompatible', $archive->errorInfo()));
@@ -241,8 +249,8 @@ class Piwik_CoreUpdater_Controller extends Piwik_Controller
         $cli = Common::isPhpCliMode() ? '_cli' : '';
         $welcomeTemplate = '@CoreUpdater/runUpdaterAndExit_welcome' . $cli;
         $doneTemplate = '@CoreUpdater/runUpdaterAndExit_done' . $cli;
-        $viewWelcome = new Piwik_View($welcomeTemplate);
-        $viewDone = new Piwik_View($doneTemplate);
+        $viewWelcome = new View($welcomeTemplate);
+        $viewDone = new View($doneTemplate);
 
         $sqlQueries = $updater->getSqlQueriesToExecute();
         if (Common::isPhpCliMode()) {
@@ -274,7 +282,7 @@ class Piwik_CoreUpdater_Controller extends Piwik_Controller
 
     private function doWelcomeUpdates($view, $componentsWithUpdateFile)
     {
-        $view->new_piwik_version = Piwik_Version::VERSION;
+        $view->new_piwik_version = Version::VERSION;
         $view->commandUpgradePiwik = "<br /><code>php " . Common::getPathToPiwikRoot() . "/index.php  -- \"module=CoreUpdater\" </code>";
         $pluginNamesToUpdate = array();
         $coreToUpdate = false;
diff --git a/plugins/CoreUpdater/CoreUpdater.php b/plugins/CoreUpdater/CoreUpdater.php
index 99c7e4029d..b682a705d5 100644
--- a/plugins/CoreUpdater/CoreUpdater.php
+++ b/plugins/CoreUpdater/CoreUpdater.php
@@ -10,6 +10,10 @@
  */
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\FrontController;
+use Piwik\Piwik_Updater;
+use Piwik\Version;
+use Piwik\UpdateCheck;
 use Piwik\Plugin;
 
 /**
@@ -32,7 +36,7 @@ class Piwik_CoreUpdater extends Plugin
 
     public static function getComponentUpdates(Piwik_Updater $updater)
     {
-        $updater->addComponentToCheck('core', Piwik_Version::VERSION);
+        $updater->addComponentToCheck('core', Version::VERSION);
         $plugins = \Piwik\PluginsManager::getInstance()->getLoadedPlugins();
         foreach ($plugins as $pluginName => $plugin) {
             $updater->addComponentToCheck($pluginName, $plugin->getVersion());
@@ -52,7 +56,7 @@ class Piwik_CoreUpdater extends Plugin
         $action = Common::getRequestVar('action', '', 'string');
 
         $updater = new Piwik_Updater();
-        $updater->addComponentToCheck('core', Piwik_Version::VERSION);
+        $updater->addComponentToCheck('core', Version::VERSION);
         $updates = $updater->getComponentsWithNewVersion();
         if (!empty($updates)) {
             Piwik::deleteAllCacheOnUpdate();
@@ -64,7 +68,7 @@ class Piwik_CoreUpdater extends Plugin
             && !($module == 'LanguagesManager'
                 && $action == 'saveLanguage')
         ) {
-            if (Piwik_FrontController::shouldRethrowException()) {
+            if (FrontController::shouldRethrowException()) {
                 throw new Exception("Piwik and/or some plugins have been upgraded to a new version. \n".
                     "--> Please run the update process first. See documentation: http://piwik.org/docs/update/ \n");
             } else {
@@ -75,6 +79,6 @@ class Piwik_CoreUpdater extends Plugin
 
     public function updateCheck()
     {
-        Piwik_UpdateCheck::check();
+        UpdateCheck::check();
     }
 }
diff --git a/plugins/CustomVariables/Archiver.php b/plugins/CustomVariables/Archiver.php
index 654cf22835..198f7a8889 100644
--- a/plugins/CustomVariables/Archiver.php
+++ b/plugins/CustomVariables/Archiver.php
@@ -3,6 +3,8 @@ use Piwik\Common;
 use Piwik\Config;
 use Piwik\DataAccess\LogAggregator;
 use Piwik\Metrics;
+use Piwik\DataArray;
+use Piwik\Tracker;
 use Piwik\PluginsArchiver;
 
 /**
@@ -21,7 +23,7 @@ class Piwik_CustomVariables_Archiver extends PluginsArchiver
     const CUSTOM_VARIABLE_RECORD_NAME = 'CustomVariables_valueByName';
 
     /**
-     * @var Piwik_DataArray
+     * @var DataArray
      */
     protected $dataArray;
     protected $maximumRowsInDataTableLevelZero;
@@ -37,9 +39,9 @@ class Piwik_CustomVariables_Archiver extends PluginsArchiver
 
     public function archiveDay()
     {
-        $this->dataArray = new Piwik_DataArray();
+        $this->dataArray = new DataArray();
 
-        for ($i = 1; $i <= Piwik_Tracker::MAX_CUSTOM_VARIABLES; $i++) {
+        for ($i = 1; $i <= Tracker::MAX_CUSTOM_VARIABLES; $i++) {
             $this->aggregateCustomVariable($i);
         }
 
@@ -190,7 +192,7 @@ class Piwik_CustomVariables_Archiver extends PluginsArchiver
         $dataArray = &$this->dataArray->getDataArray();
         foreach ($dataArray as $key => &$row) {
             if (!self::isReservedKey($key)
-                && Piwik_DataArray::isRowActions($row)
+                && DataArray::isRowActions($row)
             ) {
                 unset($row[Metrics::INDEX_NB_UNIQ_VISITORS]);
                 unset($row[Metrics::INDEX_NB_VISITS]);
diff --git a/plugins/CustomVariables/Controller.php b/plugins/CustomVariables/Controller.php
index 867988a79b..6c6054f418 100644
--- a/plugins/CustomVariables/Controller.php
+++ b/plugins/CustomVariables/Controller.php
@@ -8,22 +8,25 @@
  * @category Piwik_Plugins
  * @package Piwik_CustomVariables
  */
+use Piwik\Controller;
+use Piwik\ViewDataTable;
+use Piwik\View;
 
 /**
  * @package Piwik_CustomVariables
  */
-class Piwik_CustomVariables_Controller extends Piwik_Controller
+class Piwik_CustomVariables_Controller extends Controller
 {
     public function index($fetch = false)
     {
-        return Piwik_View::singleReport(
+        return View::singleReport(
             Piwik_Translate('CustomVariables_CustomVariables'),
             $this->getCustomVariables(true), $fetch);
     }
 
     public function getCustomVariables($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__, "CustomVariables.getCustomVariables", "getCustomVariablesValuesFromNameId");
 
         $this->setPeriodVariablesView($view);
@@ -39,7 +42,7 @@ class Piwik_CustomVariables_Controller extends Piwik_Controller
 
     public function getCustomVariablesValuesFromNameId($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__, 'CustomVariables.getCustomVariablesValuesFromNameId');
 
         $this->configureView($view);
diff --git a/plugins/CustomVariables/CustomVariables.php b/plugins/CustomVariables/CustomVariables.php
index 971a967b8e..362d453aa2 100644
--- a/plugins/CustomVariables/CustomVariables.php
+++ b/plugins/CustomVariables/CustomVariables.php
@@ -9,6 +9,7 @@
  * @package Piwik_CustomVariables
  */
 use Piwik\ArchiveProcessor;
+use Piwik\Tracker;
 use Piwik\Plugin;
 
 /**
@@ -42,7 +43,7 @@ class Piwik_CustomVariables extends Plugin
 
     public function addWidgets()
     {
-        Piwik_AddWidget('General_Visitors', 'CustomVariables_CustomVariables', 'CustomVariables', 'getCustomVariables');
+        WidgetsList::add('General_Visitors', 'CustomVariables_CustomVariables', 'CustomVariables', 'getCustomVariables');
     }
 
     public function addMenus()
@@ -79,7 +80,7 @@ class Piwik_CustomVariables extends Plugin
 
     public function getSegmentsMetadata(&$segments)
     {
-        for ($i = 1; $i <= Piwik_Tracker::MAX_CUSTOM_VARIABLES; $i++) {
+        for ($i = 1; $i <= Tracker::MAX_CUSTOM_VARIABLES; $i++) {
             $segments[] = array(
                 'type'       => 'dimension',
                 'category'   => 'CustomVariables_CustomVariables',
diff --git a/plugins/DBStats/Controller.php b/plugins/DBStats/Controller.php
index 7596dc4106..8194c29cc4 100644
--- a/plugins/DBStats/Controller.php
+++ b/plugins/DBStats/Controller.php
@@ -8,13 +8,16 @@
  * @category Piwik_Plugins
  * @package Piwik_DBStats
  */
+use Piwik\Controller\Admin;
 use Piwik\Piwik;
+use Piwik\ViewDataTable;
+use Piwik\View;
 
 /**
  *
  * @package Piwik_DBStats
  */
-class Piwik_DBStats_Controller extends Piwik_Controller_Admin
+class Piwik_DBStats_Controller extends Admin
 {
     /**
      * Returns the index for this plugin. Shows every other report defined by this plugin,
@@ -26,7 +29,7 @@ class Piwik_DBStats_Controller extends Piwik_Controller_Admin
     public function index()
     {
         Piwik::checkUserIsSuperUser();
-        $view = new Piwik_View('@DBStats/index');
+        $view = new View('@DBStats/index');
         $this->setBasicVariablesView($view);
 
         $view->databaseUsageSummary = $this->getDatabaseUsageSummary(true);
@@ -248,7 +251,7 @@ class Piwik_DBStats_Controller extends Piwik_Controller_Admin
             'estimated_size' => Piwik_Translate('DBStats_EstimatedSize')
         );
 
-        $view = Piwik_ViewDataTable::factory($viewType);
+        $view = ViewDataTable::factory($viewType);
         $view->init($this->pluginName, $function, "DBStats.$function");
         $view->setSortedColumn('label', $orderDir);
         $view->setLimit($limit);
diff --git a/plugins/DBStats/DBStats.php b/plugins/DBStats/DBStats.php
index 770e00f0ed..955c0b6812 100644
--- a/plugins/DBStats/DBStats.php
+++ b/plugins/DBStats/DBStats.php
@@ -10,6 +10,7 @@
  */
 use Piwik\Piwik;
 use Piwik\Date;
+use Piwik\ScheduledTask;
 use Piwik\Plugin;
 
 /**
@@ -45,12 +46,12 @@ class Piwik_DBStats extends Plugin
      */
     public function getScheduledTasks(&$tasks)
     {
-        $cacheDataByArchiveNameReportsTask = new Piwik_ScheduledTask(
+        $cacheDataByArchiveNameReportsTask = new ScheduledTask(
             $this,
             'cacheDataByArchiveNameReports',
             null,
             new Piwik_ScheduledTime_Weekly(),
-            Piwik_ScheduledTask::LOWEST_PRIORITY
+            ScheduledTask::LOWEST_PRIORITY
         );
         $tasks[] = $cacheDataByArchiveNameReportsTask;
     }
diff --git a/plugins/DBStats/MySQLMetadataProvider.php b/plugins/DBStats/MySQLMetadataProvider.php
index c7701e6023..c21f6f6009 100755
--- a/plugins/DBStats/MySQLMetadataProvider.php
+++ b/plugins/DBStats/MySQLMetadataProvider.php
@@ -51,7 +51,7 @@ class Piwik_DBStats_MySQLMetadataProvider
             mysql_close($link);
             $status = explode("  ", $status);
         } else {
-            $fullStatus = Piwik_FetchAssoc('SHOW STATUS');
+            $fullStatus = Db::fetchAssoc('SHOW STATUS');
             if (empty($fullStatus)) {
                 throw new Exception('Error, SHOW STATUS failed');
             }
@@ -86,7 +86,7 @@ class Piwik_DBStats_MySQLMetadataProvider
         if (!is_null($this->tableStatuses) && isset($this->tableStatuses[$prefixed])) {
             return $this->tableStatuses[$prefixed];
         } else {
-            return Piwik_FetchRow("SHOW TABLE STATUS LIKE ?", array($prefixed));
+            return Db::fetchRow("SHOW TABLE STATUS LIKE ?", array($prefixed));
         }
     }
 
@@ -105,7 +105,7 @@ class Piwik_DBStats_MySQLMetadataProvider
             $tablesPiwik = Piwik::getTablesInstalled();
 
             $this->tableStatuses = array();
-            foreach (Piwik_FetchAll("SHOW TABLE STATUS") as $t) {
+            foreach (Db::fetchAll("SHOW TABLE STATUS") as $t) {
                 if (in_array($t['Name'], $tablesPiwik)) {
                     $this->tableStatuses[$t['Name']] = $t;
                 }
@@ -232,7 +232,7 @@ class Piwik_DBStats_MySQLMetadataProvider
                 $sql = "SELECT name as 'label', COUNT(*) as 'row_count'$extraCols FROM {$status['Name']} GROUP BY name";
 
                 $table = new DataTable();
-                $table->addRowsFromSimpleArray(Piwik_FetchAll($sql));
+                $table->addRowsFromSimpleArray(Db::fetchAll($sql));
 
                 $reduceArchiveRowName = array($this, 'reduceArchiveRowName');
                 $table->filter('GroupBy', array('label', $reduceArchiveRowName));
@@ -275,7 +275,7 @@ class Piwik_DBStats_MySQLMetadataProvider
         static $fixedSizeColumnLength = null;
         if (is_null($fixedSizeColumnLength)) {
             $fixedSizeColumnLength = 0;
-            foreach (Piwik_FetchAll("SHOW COLUMNS FROM " . $status['Name']) as $column) {
+            foreach (Db::fetchAll("SHOW COLUMNS FROM " . $status['Name']) as $column) {
                 $columnType = $column['Type'];
 
                 if (($paren = strpos($columnType, '(')) !== false) {
diff --git a/plugins/Dashboard/API.php b/plugins/Dashboard/API.php
index 83a5c0b804..b3231c7bdc 100644
--- a/plugins/Dashboard/API.php
+++ b/plugins/Dashboard/API.php
@@ -155,7 +155,7 @@ class Piwik_Dashboard_API
         $module = $widget->parameters->module;
         $action = $widget->parameters->action;
 
-        return Piwik_IsWidgetDefined($module, $action);
+        return WidgetsList::isDefined($module, $action);
     }
 
     private function widgetIsNotHidden($widget)
diff --git a/plugins/Dashboard/Controller.php b/plugins/Dashboard/Controller.php
index 0f6cca6d00..c3743500b1 100644
--- a/plugins/Dashboard/Controller.php
+++ b/plugins/Dashboard/Controller.php
@@ -10,13 +10,15 @@
 use Piwik\DataTable\Renderer\Json;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\View;
 
 /**
  * Dashboard Controller
  *
  * @package Piwik_Dashboard
  */
-class Piwik_Dashboard_Controller extends Piwik_Controller
+class Piwik_Dashboard_Controller extends Controller
 {
     /**
      * @var Piwik_Dashboard
@@ -32,10 +34,10 @@ class Piwik_Dashboard_Controller extends Piwik_Controller
 
     protected function _getDashboardView($template)
     {
-        $view = new Piwik_View($template);
+        $view = new View($template);
         $this->setGeneralVariablesView($view);
 
-        $view->availableWidgets = Common::json_encode(Piwik_GetWidgetsList());
+        $view->availableWidgets = Common::json_encode(WidgetsList::get());
         $view->availableLayouts = $this->getAvailableLayouts();
 
         $view->dashboardId = Common::getRequestVar('idDashboard', 1, 'int');
@@ -68,7 +70,7 @@ class Piwik_Dashboard_Controller extends Piwik_Controller
         $this->checkTokenInUrl();
 
         Json::sendHeaderJSON();
-        echo Common::json_encode(Piwik_GetWidgetsList());
+        echo Common::json_encode(WidgetsList::get());
     }
 
     public function getDashboardLayout()
@@ -111,7 +113,7 @@ class Piwik_Dashboard_Controller extends Piwik_Controller
         $paramsBind = array($login, $idDashboard, $layout, $layout);
         $query = sprintf('INSERT INTO %s (login, iddashboard, layout) VALUES (?,?,?) ON DUPLICATE KEY UPDATE layout=?',
             Common::prefixTable('user_dashboard'));
-        Piwik_Query($query, $paramsBind);
+        Db::query($query, $paramsBind);
     }
 
     /**
@@ -126,7 +128,7 @@ class Piwik_Dashboard_Controller extends Piwik_Controller
         $paramsBind = array($name, $login, $idDashboard);
         $query = sprintf('UPDATE %s SET name = ? WHERE login = ? AND iddashboard = ?',
             Common::prefixTable('user_dashboard'));
-        Piwik_Query($query, $paramsBind);
+        Db::query($query, $paramsBind);
     }
 
     /**
@@ -146,7 +148,7 @@ class Piwik_Dashboard_Controller extends Piwik_Controller
         if ($idDashboard != 1) {
             $query = sprintf('DELETE FROM %s WHERE iddashboard = ? AND login = ?',
                 Common::prefixTable('user_dashboard'));
-            Piwik_Query($query, array($idDashboard, Piwik::getCurrentUserLogin()));
+            Db::query($query, array($idDashboard, Piwik::getCurrentUserLogin()));
         }
     }
 
@@ -196,7 +198,7 @@ class Piwik_Dashboard_Controller extends Piwik_Controller
 
         $query = sprintf('INSERT INTO %s (login, iddashboard, name, layout) VALUES (?, ?, ?, ?)',
             Common::prefixTable('user_dashboard'));
-        Piwik_Query($query, array($user, $nextId, $name, $layout));
+        Db::query($query, array($user, $nextId, $name, $layout));
 
         Json::sendHeaderJSON();
         echo Common::json_encode($nextId);
@@ -206,7 +208,7 @@ class Piwik_Dashboard_Controller extends Piwik_Controller
     {
         $nextIdQuery = sprintf('SELECT MAX(iddashboard)+1 FROM %s WHERE login = ?',
             Common::prefixTable('user_dashboard'));
-        $nextId = Piwik_FetchOne($nextIdQuery, array($login));
+        $nextId = Db::fetchOne($nextIdQuery, array($login));
 
         if (empty($nextId)) {
             $nextId = 1;
@@ -234,7 +236,7 @@ class Piwik_Dashboard_Controller extends Piwik_Controller
 
             $query = sprintf('INSERT INTO %s (login, iddashboard, name, layout) VALUES (?, ?, ?, ?)',
                 Common::prefixTable('user_dashboard'));
-            Piwik_Query($query, array($user, $nextId, $name, $layout));
+            Db::query($query, array($user, $nextId, $name, $layout));
 
             Json::sendHeaderJSON();
             echo Common::json_encode($nextId);
@@ -278,7 +280,7 @@ class Piwik_Dashboard_Controller extends Piwik_Controller
             $paramsBind = array('', '1', $layout, $layout);
             $query = sprintf('INSERT INTO %s (login, iddashboard, layout) VALUES (?,?,?) ON DUPLICATE KEY UPDATE layout=?',
                 Common::prefixTable('user_dashboard'));
-            Piwik_Query($query, $paramsBind);
+            Db::query($query, $paramsBind);
         }
     }
 
diff --git a/plugins/Dashboard/Dashboard.php b/plugins/Dashboard/Dashboard.php
index 25fb766226..c019a49573 100644
--- a/plugins/Dashboard/Dashboard.php
+++ b/plugins/Dashboard/Dashboard.php
@@ -46,7 +46,7 @@ class Piwik_Dashboard extends Plugin
         $paramsBind = array($login, $idDashboard);
         $query = sprintf('SELECT layout FROM %s WHERE login = ? AND iddashboard = ?',
             Common::prefixTable('user_dashboard'));
-        $return = Piwik_FetchAll($query, $paramsBind);
+        $return = Db::fetchAll($query, $paramsBind);
 
         if (count($return) == 0) {
             return false;
@@ -96,7 +96,7 @@ class Piwik_Dashboard extends Plugin
 
     public function getAllDashboards($login)
     {
-        $dashboards = Piwik_FetchAll('SELECT iddashboard, name, layout
+        $dashboards = Db::fetchAll('SELECT iddashboard, name, layout
                                       FROM ' . Common::prefixTable('user_dashboard') .
             ' WHERE login = ? ORDER BY iddashboard', array($login));
 
@@ -161,7 +161,7 @@ class Piwik_Dashboard extends Plugin
                 if (isset($widget->parameters->module)) {
                     $controllerName = $widget->parameters->module;
                     $controllerAction = $widget->parameters->action;
-                    if (!Piwik_IsWidgetDefined($controllerName, $controllerAction)) {
+                    if (!WidgetsList::isDefined($controllerName, $controllerAction)) {
                         unset($row[$widgetId]);
                     }
                 } else {
@@ -240,7 +240,7 @@ class Piwik_Dashboard extends Plugin
 
     public function deleteDashboardLayout($userLogin)
     {
-        Piwik_Query('DELETE FROM ' . Common::prefixTable('user_dashboard') . ' WHERE login = ?', array($userLogin));
+        Db::query('DELETE FROM ' . Common::prefixTable('user_dashboard') . ' WHERE login = ?', array($userLogin));
     }
 
     public function install()
@@ -254,7 +254,7 @@ class Piwik_Dashboard extends Plugin
 					layout TEXT NOT NULL,
 					PRIMARY KEY ( login , iddashboard )
 					)  DEFAULT CHARSET=utf8 ";
-            Piwik_Exec($sql);
+            Db::exec($sql);
         } catch (Exception $e) {
             // mysql code error 1050:table already exists
             // see bug #153 http://dev.piwik.org/trac/ticket/153
@@ -266,6 +266,6 @@ class Piwik_Dashboard extends Plugin
 
     public function uninstall()
     {
-        Piwik_DropTables(Common::prefixTable('user_dashboard'));
+        Db::dropTables(Common::prefixTable('user_dashboard'));
     }
 }
diff --git a/plugins/DevicesDetection/Controller.php b/plugins/DevicesDetection/Controller.php
index ae94f95375..d9b0136b77 100644
--- a/plugins/DevicesDetection/Controller.php
+++ b/plugins/DevicesDetection/Controller.php
@@ -1,6 +1,9 @@
 <?php
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\ViewDataTable;
+use Piwik\View;
 
 /**
  * Piwik - Open source web analytics
@@ -11,7 +14,7 @@ use Piwik\Common;
  * @category Piwik_Plugins
  * @package Piwik_DevicesDetection
  */
-class Piwik_DevicesDetection_Controller extends Piwik_Controller
+class Piwik_DevicesDetection_Controller extends Controller
 {
 
     /** The set of related reports displayed under the 'Operating Systems' header. */
@@ -33,7 +36,7 @@ class Piwik_DevicesDetection_Controller extends Piwik_Controller
 
     public function index($fetch = false)
     {
-        $view = new Piwik_View('@DevicesDetection/index');
+        $view = new View('@DevicesDetection/index');
         $view->deviceTypes = $view->deviceModels = $view->deviceBrands = $view->osReport = $view->browserReport = "blank";
         $view->deviceTypes = $this->getType(true);
         $view->deviceBrands = $this->getBrand(true);
@@ -120,7 +123,7 @@ class Piwik_DevicesDetection_Controller extends Piwik_Controller
 
     protected function getStandardDataTableUserSettings($currentControllerAction, $APItoCall, $defaultDatatableType = null)
     {
-        $view = Piwik_ViewDataTable::factory($defaultDatatableType);
+        $view = ViewDataTable::factory($defaultDatatableType);
         $view->init($this->pluginName, $currentControllerAction, $APItoCall);
         $view->disableSearchBox();
         $view->disableExcludeLowPopulation();
@@ -136,7 +139,7 @@ class Piwik_DevicesDetection_Controller extends Piwik_Controller
     {
         Piwik::checkUserIsSuperUser();
         $q = "SELECT idvisit, config_debug_ua FROM " . Common::prefixTable("log_visit");
-        $res = Piwik_FetchAll($q);
+        $res = Db::fetchAll($q);
         foreach ($res as $rec) {
             $UAParser = new UserAgentParserEnhanced($rec['config_debug_ua']);
             $UAParser->parse();
@@ -174,7 +177,7 @@ class Piwik_DevicesDetection_Controller extends Piwik_Controller
             "config_device_model = " . (isset($uaDetails['config_device_model']) ? "'" . $uaDetails['config_device_model'] . "'" : "NULL") . " ," .
             "config_device_brand = " . (isset($uaDetails['config_device_brand']) ? "'" . $uaDetails['config_device_brand'] . "'" : "NULL") . "
                     WHERE idvisit = " . $idVisit;
-        Piwik_Query($q);
+        Db::query($q);
     }
 
 }
diff --git a/plugins/DevicesDetection/DevicesDetection.php b/plugins/DevicesDetection/DevicesDetection.php
index 7129ee581b..f70fba50fa 100644
--- a/plugins/DevicesDetection/DevicesDetection.php
+++ b/plugins/DevicesDetection/DevicesDetection.php
@@ -130,7 +130,7 @@ class Piwik_DevicesDetection extends Plugin
             list($category, $name, $controllerName, $controllerAction) = $report;
             if ($category == false)
                 continue;
-            Piwik_AddWidget($category, $name, $controllerName, $controllerAction);
+            WidgetsList::add($category, $name, $controllerName, $controllerAction);
         }
     }
 
@@ -194,12 +194,12 @@ class Piwik_DevicesDetection extends Plugin
                 ADD `config_device_type` TINYINT( 10 ) NULL DEFAULT NULL AFTER `config_browser_version` ,
                 ADD `config_device_brand` VARCHAR( 100 ) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL AFTER `config_device_type` ,
                 ADD `config_device_model` VARCHAR( 100 ) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL AFTER `config_device_brand`";
-            Piwik_Exec($q1);
+            Db::exec($q1);
             // conditionaly add this column
             if (@Config::getInstance()->Debug['store_user_agent_in_visit']) {
                 $q2 = "ALTER TABLE `" . Common::prefixTable("log_visit") . "`
                 ADD `config_debug_ua` VARCHAR( 512 ) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL AFTER `config_device_model`";
-                Piwik_Exec($q2);
+                Db::exec($q2);
             }
         } catch (Exception $e) {
            if (!Zend_Registry::get('db')->isErrNo($e, '1060')) {
diff --git a/plugins/ExampleAPI/API.php b/plugins/ExampleAPI/API.php
index d4a0febccf..214d73eac5 100644
--- a/plugins/ExampleAPI/API.php
+++ b/plugins/ExampleAPI/API.php
@@ -11,6 +11,7 @@
 use Piwik\DataTable\Row;
 use Piwik\Piwik;
 use Piwik\DataTable;
+use Piwik\Version;
 
 /**
  * The ExampleAPI is useful to developers building a custom Piwik plugin.
@@ -61,7 +62,7 @@ class Piwik_ExampleAPI_API
     public function getPiwikVersion()
     {
         Piwik::checkUserHasSomeViewAccess();
-        return Piwik_Version::VERSION;
+        return Version::VERSION;
     }
 
     /**
diff --git a/plugins/ExamplePlugin/Controller.php b/plugins/ExamplePlugin/Controller.php
index 3e6c557130..0bebd89e57 100644
--- a/plugins/ExamplePlugin/Controller.php
+++ b/plugins/ExamplePlugin/Controller.php
@@ -10,12 +10,14 @@
  */
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\View;
 
 /**
  *
  * @package Piwik_ExamplePlugin
  */
-class Piwik_ExamplePlugin_Controller extends Piwik_Controller
+class Piwik_ExamplePlugin_Controller extends Controller
 {
     /**
      * Go to /piwik/?module=ExamplePlugin&action=helloWorld to execute this method
@@ -54,7 +56,7 @@ class Piwik_ExamplePlugin_Controller extends Piwik_Controller
      */
     public function piwikDownloads()
     {
-        $view = new Piwik_View('@ExamplePlugin/piwikDownloads');
+        $view = new View('@ExamplePlugin/piwikDownloads');
         $this->setGeneralVariablesView($view);
         echo $view->render();
     }
@@ -81,7 +83,7 @@ class Piwik_ExamplePlugin_Controller extends Piwik_Controller
 
         $out .= '<h3>Misc</h3>';
         $out .= '<code>Piwik_AddMenu( $mainMenuName, $subMenuName, $url );</code> - Adds an entry to the menu in the Piwik interface (See the example in the <a href="https://github.com/piwik/piwik/blob/1.0/plugins/UserCountry/UserCountry.php#L76">UserCountry Plugin file</a>)<br />';
-        $out .= '<code>Piwik_AddWidget( $widgetCategory, $widgetName, $controllerName, $controllerAction, $customParameters = array());</code> - Adds a widget that users can add in the dashboard, or export using the Widgets link at the top of the screen. See the example in the <a href="https://github.com/piwik/piwik/blob/1.0/plugins/UserCountry/UserCountry.php#L70">UserCountry Plugin file</a> or any other plugin)<br />';
+        $out .= '<code>WidgetsList::add( $widgetCategory, $widgetName, $controllerName, $controllerAction, $customParameters = array());</code> - Adds a widget that users can add in the dashboard, or export using the Widgets link at the top of the screen. See the example in the <a href="https://github.com/piwik/piwik/blob/1.0/plugins/UserCountry/UserCountry.php#L70">UserCountry Plugin file</a> or any other plugin)<br />';
         $out .= '<code>Common::prefixTable("site")</code> = <b>' . Common::prefixTable("site") . '</b><br />';
 
 
@@ -94,15 +96,15 @@ class Piwik_ExamplePlugin_Controller extends Piwik_Controller
 
         $out .= '<h2>Execute SQL queries</h2>';
         $txtQuery = "SELECT token_auth FROM " . Common::prefixTable('user') . " WHERE login = ?";
-        $result = Piwik_FetchOne($txtQuery, array('anonymous'));
-        $out .= '<code>Piwik_FetchOne("' . $txtQuery . '", array("anonymous"))</code> = <b>' . var_export($result, true) . '</b><br />';
+        $result = Db::fetchOne($txtQuery, array('anonymous'));
+        $out .= '<code>Db::fetchOne("' . $txtQuery . '", array("anonymous"))</code> = <b>' . var_export($result, true) . '</b><br />';
         $out .= '<br />';
 
-        $query = Piwik_Query($txtQuery, array('anonymous'));
+        $query = Db::query($txtQuery, array('anonymous'));
         $fetched = $query->fetch();
         $token_auth = $fetched['token_auth'];
 
-        $out .= '<code>$query = Piwik_Query("' . $txtQuery . '", array("anonymous"))</code><br />';
+        $out .= '<code>$query = Db::query("' . $txtQuery . '", array("anonymous"))</code><br />';
         $out .= '<code>$fetched = $query->fetch();</code><br />';
         $out .= 'At this point, we have: <code>$fetched[\'token_auth\'] == <b>' . var_export($token_auth, true) . '</b></code><br />';
 
diff --git a/plugins/ExamplePlugin/ExamplePlugin.php b/plugins/ExamplePlugin/ExamplePlugin.php
index 7fc7a2cc09..bb7c968452 100644
--- a/plugins/ExamplePlugin/ExamplePlugin.php
+++ b/plugins/ExamplePlugin/ExamplePlugin.php
@@ -51,8 +51,8 @@ class Piwik_ExamplePlugin extends Plugin
     {
         // we register the widgets so they appear in the "Add a new widget" window in the dashboard
         // Note that the first two parameters can be either a normal string, or an index to a translation string
-        Piwik_AddWidget('ExamplePlugin_exampleWidgets', 'ExamplePlugin_exampleWidget', 'ExamplePlugin', 'exampleWidget');
-        Piwik_AddWidget('ExamplePlugin_exampleWidgets', 'ExamplePlugin_photostreamMatt', 'ExamplePlugin', 'photostreamMatt');
-        Piwik_AddWidget('ExamplePlugin_exampleWidgets', 'ExamplePlugin_piwikForumVisits', 'ExamplePlugin', 'piwikDownloads');
+        WidgetsList::add('ExamplePlugin_exampleWidgets', 'ExamplePlugin_exampleWidget', 'ExamplePlugin', 'exampleWidget');
+        WidgetsList::add('ExamplePlugin_exampleWidgets', 'ExamplePlugin_photostreamMatt', 'ExamplePlugin', 'photostreamMatt');
+        WidgetsList::add('ExamplePlugin_exampleWidgets', 'ExamplePlugin_piwikForumVisits', 'ExamplePlugin', 'piwikDownloads');
     }
 }
diff --git a/plugins/ExampleRssWidget/Controller.php b/plugins/ExampleRssWidget/Controller.php
index 41e6691f9d..aaa53a7ef1 100644
--- a/plugins/ExampleRssWidget/Controller.php
+++ b/plugins/ExampleRssWidget/Controller.php
@@ -8,12 +8,13 @@
  * @category Piwik_Plugins
  * @package Piwik_ExampleRssWidget
  */
+use Piwik\Controller;
 
 /**
  *
  * @package Piwik_ExampleRssWidget
  */
-class Piwik_ExampleRssWidget_Controller extends Piwik_Controller
+class Piwik_ExampleRssWidget_Controller extends Controller
 {
     public function rssPiwik()
     {
diff --git a/plugins/ExampleRssWidget/ExampleRssWidget.php b/plugins/ExampleRssWidget/ExampleRssWidget.php
index 72831e6d0b..a0f7b33dca 100644
--- a/plugins/ExampleRssWidget/ExampleRssWidget.php
+++ b/plugins/ExampleRssWidget/ExampleRssWidget.php
@@ -34,7 +34,7 @@ class Piwik_ExampleRssWidget extends Plugin
 
     public function addWidgets()
     {
-        Piwik_AddWidget('Example Widgets', 'Piwik.org Blog', 'ExampleRssWidget', 'rssPiwik');
-        Piwik_AddWidget('Example Widgets', 'Piwik Changelog', 'ExampleRssWidget', 'rssChangelog');
+        WidgetsList::add('Example Widgets', 'Piwik.org Blog', 'ExampleRssWidget', 'rssPiwik');
+        WidgetsList::add('Example Widgets', 'Piwik Changelog', 'ExampleRssWidget', 'rssChangelog');
     }
 }
diff --git a/plugins/ExampleUI/API.php b/plugins/ExampleUI/API.php
index 5857ef112b..3730c54eba 100644
--- a/plugins/ExampleUI/API.php
+++ b/plugins/ExampleUI/API.php
@@ -44,7 +44,7 @@ class Piwik_ExampleUI_API
 						AND date < ?
 					GROUP BY date
 					ORDER BY date ASC";
-        //$result = Piwik_FetchAll($query, array($dateStart, $dateEnd));
+        //$result = Db::fetchAll($query, array($dateStart, $dateEnd));
         // to keep things simple, we generate the data
         foreach ($period->getSubperiods() as $subPeriod) {
             $server1 = mt_rand(50, 90);
diff --git a/plugins/ExampleUI/Controller.php b/plugins/ExampleUI/Controller.php
index 5ee8ffddd7..ffb9342830 100644
--- a/plugins/ExampleUI/Controller.php
+++ b/plugins/ExampleUI/Controller.php
@@ -9,15 +9,18 @@
  * @package Piwik_ExampleUI
  */
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\ViewDataTable;
+use Piwik\View;
 
 /**
  * @package Piwik_ExampleUI
  */
-class Piwik_ExampleUI_Controller extends Piwik_Controller
+class Piwik_ExampleUI_Controller extends Controller
 {
     function dataTables()
     {
-        $view = Piwik_ViewDataTable::factory('table');
+        $view = ViewDataTable::factory('table');
         $view->init($this->pluginName, __FUNCTION__, 'ExampleUI.getTemperatures');
         $view->setColumnTranslation('value', "Temperature in °C");
         $view->setColumnTranslation('label', "Hour of day");
@@ -39,7 +42,7 @@ class Piwik_ExampleUI_Controller extends Piwik_Controller
 
     function echoEvolutionGraph()
     {
-        $view = Piwik_ViewDataTable::factory('graphEvolution');
+        $view = ViewDataTable::factory('graphEvolution');
         $view->init($this->pluginName, __FUNCTION__, 'ExampleUI.getTemperaturesEvolution');
         $view->setColumnTranslation('server1', "Temperature server piwik.org");
         $view->setColumnTranslation('server2', "Temperature server dev.piwik.org");
@@ -49,7 +52,7 @@ class Piwik_ExampleUI_Controller extends Piwik_Controller
 
     function barGraph()
     {
-        $view = Piwik_ViewDataTable::factory('graphVerticalBar');
+        $view = ViewDataTable::factory('graphVerticalBar');
         $view->init($this->pluginName, __FUNCTION__, 'ExampleUI.getTemperatures');
         $view->setColumnTranslation('value', "Temperature");
         $view->setAxisYUnit('°C');
@@ -60,7 +63,7 @@ class Piwik_ExampleUI_Controller extends Piwik_Controller
 
     function pieGraph()
     {
-        $view = Piwik_ViewDataTable::factory('graphPie');
+        $view = ViewDataTable::factory('graphPie');
         $view->init($this->pluginName, __FUNCTION__, 'ExampleUI.getPlanetRatios');
         $view->setColumnsToDisplay('value');
         $view->setColumnTranslation('value', "times the diameter of Earth");
@@ -84,7 +87,7 @@ class Piwik_ExampleUI_Controller extends Piwik_Controller
 
     function echoSimpleTagClouds()
     {
-        $view = Piwik_ViewDataTable::factory('cloud');
+        $view = ViewDataTable::factory('cloud');
         $view->init($this->pluginName, __FUNCTION__, 'ExampleUI.getPlanetRatios');
         $view->setColumnsToDisplay(array('label', 'value'));
         $view->setColumnTranslation('value', "times the diameter of Earth");
@@ -94,7 +97,7 @@ class Piwik_ExampleUI_Controller extends Piwik_Controller
 
     function echoAdvancedTagClouds()
     {
-        $view = Piwik_ViewDataTable::factory('cloud');
+        $view = ViewDataTable::factory('cloud');
         $view->init($this->pluginName, __FUNCTION__, 'ExampleUI.getPlanetRatiosWithLogos');
         $view->setDisplayLogoInTagCloud(true);
         $view->disableFooterExceptExportIcons();
@@ -105,7 +108,7 @@ class Piwik_ExampleUI_Controller extends Piwik_Controller
 
     function sparklines()
     {
-        $view = new Piwik_View('@ExampleUI/sparklines');
+        $view = new View('@ExampleUI/sparklines');
         $view->urlSparkline1 = $this->getUrlSparkline('generateSparkline', array('server' => 'server1', 'rand' => mt_rand()));
         $view->urlSparkline2 = $this->getUrlSparkline('generateSparkline', array('server' => 'server2', 'rand' => mt_rand()));
         echo $view->render();
@@ -114,7 +117,7 @@ class Piwik_ExampleUI_Controller extends Piwik_Controller
     function generateSparkline()
     {
         $serverRequested = Common::getRequestVar('server', '');
-        $view = Piwik_ViewDataTable::factory('sparkline');
+        $view = ViewDataTable::factory('sparkline');
         $view->init($this->pluginName, __FUNCTION__, 'ExampleUI.getTemperaturesEvolution');
         $view->setColumnsToDisplay($serverRequested);
         $this->renderView($view);
diff --git a/plugins/Feedback/Controller.php b/plugins/Feedback/Controller.php
index 243a36bacd..3a43559d6f 100644
--- a/plugins/Feedback/Controller.php
+++ b/plugins/Feedback/Controller.php
@@ -11,17 +11,24 @@
 use Piwik\Config;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\IP;
+use Piwik\Mail;
+use Piwik\Nonce;
+use Piwik\View;
+use Piwik\Version;
+use Piwik\Url;
 
 /**
  *
  * @package Piwik_Feedback
  */
-class Piwik_Feedback_Controller extends Piwik_Controller
+class Piwik_Feedback_Controller extends Controller
 {
     function index()
     {
-        $view = new Piwik_View('@Feedback/index');
-        $view->nonce = Piwik_Nonce::getNonce('Piwik_Feedback.sendFeedback', 3600);
+        $view = new View('@Feedback/index');
+        $view->nonce = Nonce::getNonce('Piwik_Feedback.sendFeedback', 3600);
         echo $view->render();
     }
 
@@ -36,7 +43,7 @@ class Piwik_Feedback_Controller extends Piwik_Controller
         $category = Common::getRequestVar('category', '', 'string');
         $nonce = Common::getRequestVar('nonce', '', 'string');
 
-        $view = new Piwik_View('@Feedback/sendFeedback');
+        $view = new View('@Feedback/sendFeedback');
         $view->feedbackEmailAddress = Config::getInstance()->General['feedback_email_address'];
         try {
             $minimumBodyLength = 40;
@@ -53,19 +60,19 @@ class Piwik_Feedback_Controller extends Piwik_Controller
             if (preg_match('/https?:/i', $body)) {
                 throw new Exception(Piwik_TranslateException('Feedback_ExceptionNoUrls'));
             }
-            if (!Piwik_Nonce::verifyNonce('Piwik_Feedback.sendFeedback', $nonce)) {
+            if (!Nonce::verifyNonce('Piwik_Feedback.sendFeedback', $nonce)) {
                 throw new Exception(Piwik_TranslateException('General_ExceptionNonceMismatch'));
             }
-            Piwik_Nonce::discardNonce('Piwik_Feedback.sendFeedback');
+            Nonce::discardNonce('Piwik_Feedback.sendFeedback');
 
-            $mail = new Piwik_Mail();
+            $mail = new Mail();
             $mail->setFrom(Common::unsanitizeInputValue($email));
             $mail->addTo($view->feedbackEmailAddress, 'Piwik Team');
             $mail->setSubject('[ Feedback form - Piwik ] ' . $category);
             $mail->setBodyText(Common::unsanitizeInputValue($body) . "\n"
-                . 'Piwik ' . Piwik_Version::VERSION . "\n"
-                . 'IP: ' . Piwik_IP::getIpFromHeader() . "\n"
-                . 'URL: ' . Piwik_Url::getReferer() . "\n");
+                . 'Piwik ' . Version::VERSION . "\n"
+                . 'IP: ' . IP::getIpFromHeader() . "\n"
+                . 'URL: ' . Url::getReferer() . "\n");
             @$mail->send();
         } catch (Exception $e) {
             $view->errorString = $e->getMessage();
diff --git a/plugins/Goals/API.php b/plugins/Goals/API.php
index db754b3bb3..2f5be105ba 100644
--- a/plugins/Goals/API.php
+++ b/plugins/Goals/API.php
@@ -65,7 +65,7 @@ class Piwik_Goals_API
             return array();
         }
         Piwik::checkUserHasViewAccess($idSite);
-        $goals = Piwik_FetchAll("SELECT *
+        $goals = Db::fetchAll("SELECT *
 								FROM " . Common::prefixTable('goal') . "
 								WHERE idsite IN (" . implode(", ", $idSite) . ")
 									AND deleted = 0");
@@ -194,12 +194,12 @@ class Piwik_Goals_API
     public function deleteGoal($idSite, $idGoal)
     {
         Piwik::checkUserHasAdminAccess($idSite);
-        Piwik_Query("UPDATE " . Common::prefixTable('goal') . "
+        Db::query("UPDATE " . Common::prefixTable('goal') . "
 										SET deleted = 1
 										WHERE idsite = ? 
 											AND idgoal = ?",
             array($idSite, $idGoal));
-        Piwik_DeleteAllRows(Common::prefixTable("log_conversion"), "WHERE idgoal = ?", 100000, array($idGoal));
+        Db::deleteAllRows(Common::prefixTable("log_conversion"), "WHERE idgoal = ?", 100000, array($idGoal));
         Piwik_Tracker_Cache::regenerateCacheWebsiteAttributes($idSite);
     }
 
diff --git a/plugins/Goals/Archiver.php b/plugins/Goals/Archiver.php
index 96792174c1..000de7d136 100644
--- a/plugins/Goals/Archiver.php
+++ b/plugins/Goals/Archiver.php
@@ -12,6 +12,7 @@
 use Piwik\DataAccess\LogAggregator;
 use Piwik\Metrics;
 use Piwik\DataTable;
+use Piwik\DataArray;
 use Piwik\PluginsArchiver;
 
 class Piwik_Goals_Archiver extends PluginsArchiver
@@ -108,7 +109,7 @@ class Piwik_Goals_Archiver extends PluginsArchiver
         }
 
         $totalConversions = $totalRevenue = 0;
-        $goals = new Piwik_DataArray();
+        $goals = new DataArray();
         $visitsToConversions = $daysToConversions = array();
 
         $conversionMetrics = $this->getLogAggregator()->getConversionsMetricFields();
@@ -161,7 +162,7 @@ class Piwik_Goals_Archiver extends PluginsArchiver
         $this->getProcessor()->insertNumericRecords($metrics);
     }
 
-    protected function getConversionsNumericMetrics(Piwik_DataArray $goals)
+    protected function getConversionsNumericMetrics(DataArray $goals)
     {
         $numericRecords = array();
         $goals = $goals->getDataArray();
@@ -246,14 +247,14 @@ class Piwik_Goals_Archiver extends PluginsArchiver
     {
         foreach ($this->getEcommerceIdGoals() as $ecommerceType) {
             foreach ($this->dimensionRecord as $dimension => $record) {
-                $this->itemReports[$dimension][$ecommerceType] = new Piwik_DataArray();
+                $this->itemReports[$dimension][$ecommerceType] = new DataArray();
             }
         }
     }
 
     protected function recordItemReports()
     {
-        /** @var Piwik_DataArray $array */
+        /** @var DataArray $array */
         foreach ($this->itemReports as $dimension => $itemAggregatesByType) {
             foreach ($itemAggregatesByType as $ecommerceType => $itemAggregate) {
                 $recordName = $this->dimensionRecord[$dimension];
diff --git a/plugins/Goals/Controller.php b/plugins/Goals/Controller.php
index 64ab750b6b..953f73cf51 100644
--- a/plugins/Goals/Controller.php
+++ b/plugins/Goals/Controller.php
@@ -8,16 +8,21 @@
  * @category Piwik_Plugins
  * @package Piwik_Goals
  */
+use Piwik\API\Request;
 use Piwik\DataTable\Filter\AddColumnsProcessedMetricsGoal;
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\DataTable;
+use Piwik\Controller;
+use Piwik\FrontController;
+use Piwik\ViewDataTable;
+use Piwik\View;
 
 /**
  *
  * @package Piwik_Goals
  */
-class Piwik_Goals_Controller extends Piwik_Controller
+class Piwik_Goals_Controller extends Controller
 {
     const CONVERSION_RATE_PRECISION = 1;
 
@@ -92,14 +97,14 @@ class Piwik_Goals_Controller extends Piwik_Controller
         $_GET['filterEcommerce'] = Common::getRequestVar('filterEcommerce', 1, 'int');
         $_GET['widget'] = 1;
         $_GET['segment'] = 'visitEcommerceStatus!=none';
-        $output = Piwik_FrontController::getInstance()->dispatch('Live', 'getVisitorLog', array($fetch));
+        $output = FrontController::getInstance()->dispatch('Live', 'getVisitorLog', array($fetch));
         $_GET = $saveGET;
         return $output;
     }
 
     protected function getGoalReportView($idGoal = false)
     {
-        $view = new Piwik_View('@Goals/getGoalReportView');
+        $view = new View('@Goals/getGoalReportView');
         if ($idGoal == Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_ORDER) {
             $goalDefinition['name'] = Piwik_Translate('Goals_Ecommerce');
             $goalDefinition['allow_multiple'] = true;
@@ -171,7 +176,7 @@ class Piwik_Goals_Controller extends Piwik_Controller
 
     protected function getOverviewView()
     {
-        $view = new Piwik_View('@Goals/getOverviewView');
+        $view = new View('@Goals/getOverviewView');
         $this->setGeneralVariablesView($view);
 
         $view->graphEvolution = $this->getEvolutionGraph(true, array('nb_conversions'));
@@ -183,7 +188,7 @@ class Piwik_Goals_Controller extends Piwik_Controller
         $view->urlSparklineRevenue = $this->getUrlSparkline('getEvolutionGraph', array('columns' => array('revenue'), 'idGoal' => ''));
 
         // Pass empty idGoal will return Goal overview
-        $request = new Piwik_API_Request("method=Goals.get&format=original&idGoal=");
+        $request = new Request("method=Goals.get&format=original&idGoal=");
         $datatable = $request->process();
         $dataRow = $datatable->getFirstRow();
         $view->nb_conversions = $dataRow->getColumn('nb_conversions');
@@ -225,7 +230,7 @@ class Piwik_Goals_Controller extends Piwik_Controller
 
     public function addNewGoal()
     {
-        $view = new Piwik_View('@Goals/addNewGoal');
+        $view = new View('@Goals/addNewGoal');
         $this->setGeneralVariablesView($view);
         $view->userCanEditGoals = Piwik::isUserHasAdminAccess($this->idSite);
         $view->onlyShowAddNewGoal = true;
@@ -312,7 +317,7 @@ class Piwik_Goals_Controller extends Piwik_Controller
         }
         $topDimensions = array();
         foreach ($topDimensionsToLoad as $dimensionName => $apiMethod) {
-            $request = new Piwik_API_Request("method=$apiMethod
+            $request = new Request("method=$apiMethod
 								&format=original
 								&filter_update_columns_when_show_all_goals=1
 								&idGoal=" . AddColumnsProcessedMetricsGoal::GOALS_FULL_TABLE . "
@@ -348,7 +353,7 @@ class Piwik_Goals_Controller extends Piwik_Controller
 
     protected function getMetricsForGoal($idGoal)
     {
-        $request = new Piwik_API_Request("method=Goals.get&format=original&idGoal=$idGoal");
+        $request = new Request("method=Goals.get&format=original&idGoal=$idGoal");
         $datatable = $request->process();
         $dataRow = $datatable->getFirstRow();
         $nbConversions = $dataRow->getColumn('nb_conversions');
@@ -454,26 +459,26 @@ class Piwik_Goals_Controller extends Piwik_Controller
 
     public function getItemsSku($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
     
     public function getItemsName($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getItemsCategory($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getVisitsUntilConversion($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getDaysToConversion($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 }
diff --git a/plugins/Goals/Goals.php b/plugins/Goals/Goals.php
index cd9857e3fd..a12ce89280 100644
--- a/plugins/Goals/Goals.php
+++ b/plugins/Goals/Goals.php
@@ -11,6 +11,7 @@
 use Piwik\ArchiveProcessor;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\TranslationWriter;
 use Piwik\Plugin;
 use Piwik\Site;
 
@@ -102,7 +103,7 @@ class Piwik_Goals extends Plugin
      */
     function deleteSiteGoals($idSite)
     {
-        Piwik_Query("DELETE FROM " . Common::prefixTable('goal') . " WHERE idsite = ? ", array($idSite));
+        Db::query("DELETE FROM " . Common::prefixTable('goal') . " WHERE idsite = ? ", array($idSite));
     }
 
     /**
@@ -418,19 +419,19 @@ class Piwik_Goals extends Plugin
         // Ecommerce widgets
         $site = new Site($idSite);
         if ($site->isEcommerceEnabled()) {
-            Piwik_AddWidget('Goals_Ecommerce', 'Goals_EcommerceOverview', 'Goals', 'widgetGoalReport', array('idGoal' => Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_ORDER));
-            Piwik_AddWidget('Goals_Ecommerce', 'Goals_EcommerceLog', 'Goals', 'getEcommerceLog');
+            WidgetsList::add('Goals_Ecommerce', 'Goals_EcommerceOverview', 'Goals', 'widgetGoalReport', array('idGoal' => Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_ORDER));
+            WidgetsList::add('Goals_Ecommerce', 'Goals_EcommerceLog', 'Goals', 'getEcommerceLog');
             foreach ($this->ecommerceReports as $widget) {
-                Piwik_AddWidget('Goals_Ecommerce', $widget[0], $widget[1], $widget[2]);
+                WidgetsList::add('Goals_Ecommerce', $widget[0], $widget[1], $widget[2]);
             }
         }
 
         // Goals widgets
-        Piwik_AddWidget('Goals_Goals', 'Goals_GoalsOverview', 'Goals', 'widgetGoalsOverview');
+        WidgetsList::add('Goals_Goals', 'Goals_GoalsOverview', 'Goals', 'widgetGoalsOverview');
         $goals = Piwik_Goals_API::getInstance()->getGoals($idSite);
         if (count($goals) > 0) {
             foreach ($goals as $goal) {
-                Piwik_AddWidget('Goals_Goals', Common::sanitizeInputValue($goal['name']), 'Goals', 'widgetGoalReport', array('idGoal' => $goal['idgoal']));
+                WidgetsList::add('Goals_Goals', Common::sanitizeInputValue($goal['name']), 'Goals', 'widgetGoalReport', array('idGoal' => $goal['idgoal']));
             }
         }
     }
@@ -465,7 +466,7 @@ class Piwik_Goals extends Plugin
             }
             Piwik_AddMenu($mainGoalMenu, 'Goals_GoalsOverview', array('module' => 'Goals', 'action' => 'index'), true, 2);
             foreach ($goals as $goal) {
-                Piwik_AddMenu($mainGoalMenu, str_replace('%', '%%', Piwik_TranslationWriter::clean($goal['name'])), array('module' => 'Goals', 'action' => 'goalReport', 'idGoal' => $goal['idgoal']));
+                Piwik_AddMenu($mainGoalMenu, str_replace('%', '%%', TranslationWriter::clean($goal['name'])), array('module' => 'Goals', 'action' => 'goalReport', 'idGoal' => $goal['idgoal']));
             }
         }
     }
diff --git a/plugins/ImageGraph/API.php b/plugins/ImageGraph/API.php
index b2811772f0..dafd9d9399 100644
--- a/plugins/ImageGraph/API.php
+++ b/plugins/ImageGraph/API.php
@@ -283,7 +283,7 @@ class Piwik_ImageGraph_API
                 $plottedMetric = reset($ordinateColumns);
 
                 // when no labels are specified, getRowEvolution returns the top N=filter_limit row evolutions
-                // rows are sorted using filter_sort_column (see Piwik_API_DataTableGenericFilter for more info)
+                // rows are sorted using filter_sort_column (see DataTableGenericFilter for more info)
                 if (!$labels) {
                     $savedFilterSortColumnValue = Common::getRequestVar('filter_sort_column', '');
                     $_GET['filter_sort_column'] = $plottedMetric;
diff --git a/plugins/ImageGraph/Controller.php b/plugins/ImageGraph/Controller.php
index cd7700ef23..a36d520b8e 100644
--- a/plugins/ImageGraph/Controller.php
+++ b/plugins/ImageGraph/Controller.php
@@ -1,6 +1,8 @@
 <?php
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\View;
 
 /**
  * Piwik - Open source web analytics
@@ -12,7 +14,7 @@ use Piwik\Common;
  * @package Piwik_ImageGraph
  */
 
-class Piwik_ImageGraph_Controller extends Piwik_Controller
+class Piwik_ImageGraph_Controller extends Controller
 {
     // Call metadata reports, and draw the default graph for each report.
     public function index()
@@ -34,7 +36,7 @@ class Piwik_ImageGraph_Controller extends Piwik_Controller
                 );
             }
         }
-        $view = new Piwik_View('@ImageGraph/index');
+        $view = new View('@ImageGraph/index');
         $view->titleAndUrls = $plot;
         echo $view->render();
     }
@@ -44,7 +46,7 @@ class Piwik_ImageGraph_Controller extends Piwik_Controller
     {
         Piwik::checkUserIsSuperUser();
 
-        $view = new Piwik_View('@ImageGraph/testAllSizes');
+        $view = new View('@ImageGraph/testAllSizes');
         $this->setGeneralVariablesView($view);
 
         $period = Common::getRequestVar('period', 'day', 'string');
diff --git a/plugins/ImageGraph/ImageGraph.php b/plugins/ImageGraph/ImageGraph.php
index 3a2f56bb58..6181877fb7 100644
--- a/plugins/ImageGraph/ImageGraph.php
+++ b/plugins/ImageGraph/ImageGraph.php
@@ -1,6 +1,8 @@
 <?php
 use Piwik\Common;
 use Piwik\Period;
+use Piwik\Controller;
+use Piwik\Url;
 use Piwik\Plugin;
 use Piwik\Site;
 use Piwik\Config;
@@ -28,7 +30,7 @@ class Piwik_ImageGraph extends Plugin
 
     public function getInformation()
     {
-        $suffix = ' Debug: <a href="' . Piwik_Url::getCurrentQueryStringWithParametersModified(
+        $suffix = ' Debug: <a href="' . Url::getCurrentQueryStringWithParametersModified(
             array('module' => 'ImageGraph', 'action' => 'index')) . '">All images</a>';
         $info = parent::getInformation();
         $info['description'] .= ' ' . $suffix;
@@ -90,7 +92,7 @@ class Piwik_ImageGraph extends Plugin
                 $dateForMultiplePeriodGraph = $dateForSinglePeriodGraph;
             } else {
                 $periodForMultiplePeriodGraph = $periodForSinglePeriodGraph;
-                $dateForMultiplePeriodGraph = Piwik_Controller::getDateRangeRelativeToEndDate(
+                $dateForMultiplePeriodGraph = Controller::getDateRangeRelativeToEndDate(
                     $periodForSinglePeriodGraph,
                     'last' . self::GRAPH_EVOLUTION_LAST_PERIODS,
                     $dateForSinglePeriodGraph,
@@ -135,7 +137,7 @@ class Piwik_ImageGraph extends Plugin
                 $parameters['idSubtable'] = $idSubtable;
             }
 
-            $report['imageGraphUrl'] = $urlPrefix . Piwik_Url::getQueryStringFromParameters($parameters);
+            $report['imageGraphUrl'] = $urlPrefix . Url::getQueryStringFromParameters($parameters);
 
             // thanks to API.getRowEvolution, reports with dimensions can now be plotted using an evolution graph
             // however, most reports with a fixed set of dimension values are excluded
@@ -148,7 +150,7 @@ class Piwik_ImageGraph extends Plugin
                 && $reportWithDimensionsSupportsEvolution) {
                 $parameters['period'] = $periodForMultiplePeriodGraph;
                 $parameters['date'] = $dateForMultiplePeriodGraph;
-                $report['imageGraphEvolutionUrl'] = $urlPrefix . Piwik_Url::getQueryStringFromParameters($parameters);
+                $report['imageGraphEvolutionUrl'] = $urlPrefix . Url::getQueryStringFromParameters($parameters);
             }
         }
     }
diff --git a/plugins/Installation/Controller.php b/plugins/Installation/Controller.php
index 5fcfcbe39a..f661b3dd98 100644
--- a/plugins/Installation/Controller.php
+++ b/plugins/Installation/Controller.php
@@ -8,18 +8,27 @@
  * @category Piwik_Plugins
  * @package Piwik_Installation
  */
+use Piwik\API\Request;
+use Piwik\Controller\Admin;
 use Piwik\DataAccess\ArchiveTableCreator;
+use Piwik\Db\Adapter;
 use Piwik\Piwik;
 use Piwik\Config;
 use Piwik\Common;
 use Piwik\Access;
+use Piwik\Http;
+use Piwik\Piwik_Updater;
+use Piwik\View;
+use Piwik\Version;
+use Piwik\Url;
+use Piwik\ProxyHeaders;
 
 /**
  * Installation controller
  *
  * @package Piwik_Installation
  */
-class Piwik_Installation_Controller extends Piwik_Controller_Admin
+class Piwik_Installation_Controller extends Admin
 {
     // public so plugins can add/delete installation steps
     public $steps = array(
@@ -286,7 +295,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
             Piwik::createAnonymousUser();
 
             $updater = new Piwik_Updater();
-            $updater->recordComponentSuccessfullyUpdated('core', Piwik_Version::VERSION);
+            $updater->recordComponentSuccessfullyUpdated('core', Version::VERSION);
             $view->tablesCreated = true;
             $view->showNextStep = true;
         }
@@ -327,7 +336,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
                 'email'     => $form->getSubmitValue('email'),
                 'security'  => $form->getSubmitValue('subscribe_newsletter_security'),
                 'community' => $form->getSubmitValue('subscribe_newsletter_community'),
-                'url'       => Piwik_Url::getCurrentUrlWithoutQueryString(),
+                'url'       => Url::getCurrentUrlWithoutQueryString(),
             );
             if ($params['security'] == '1'
                 || $params['community'] == '1'
@@ -340,7 +349,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
                 }
                 $url .= '?' . http_build_query($params, '', '&');
                 try {
-                    Piwik_Http::sendHttpRequest($url, $timeout = 2);
+                    Http::sendHttpRequest($url, $timeout = 2);
                 } catch (Exception $e) {
                     // e.g., disable_functions = fsockopen; allow_url_open = Off
                 }
@@ -378,7 +387,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
             $url = urlencode($form->getSubmitValue('url'));
             $ecommerce = (int)$form->getSubmitValue('ecommerce');
 
-            $request = new Piwik_API_Request("
+            $request = new Request("
 							method=SitesManager.addSite
 							&siteName=$name
 							&urls=$url
@@ -425,11 +434,11 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
         $idSite = $this->session->site_idSite;
 
         // Load the Tracking code and help text from the SitesManager
-        $viewTrackingHelp = new Piwik_View('@SitesManager/_displayJavascriptCode');
+        $viewTrackingHelp = new View('@SitesManager/_displayJavascriptCode');
         $viewTrackingHelp->displaySiteName = $siteName;
-        $viewTrackingHelp->jsTag = Piwik::getJavascriptCode($idSite, Piwik_Url::getCurrentUrlWithoutFileName());
+        $viewTrackingHelp->jsTag = Piwik::getJavascriptCode($idSite, Url::getCurrentUrlWithoutFileName());
         $viewTrackingHelp->idSite = $idSite;
-        $viewTrackingHelp->piwikUrl = Piwik_Url::getCurrentUrlWithoutFileName();
+        $viewTrackingHelp->piwikUrl = Url::getCurrentUrlWithoutFileName();
 
         $view->trackingHelp = $viewTrackingHelp->render();
         $view->displaySiteName = $siteName;
@@ -478,7 +487,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
     {
         Piwik::checkUserIsSuperUser();
 
-        $view = new Piwik_View('@Installation/systemCheckPage');
+        $view = new View('@Installation/systemCheckPage');
         $this->setBasicVariablesView($view);
 
         $view->duringInstall = false;
@@ -501,7 +510,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
         $this->createDbFromSessionInformation();
 
         Piwik::setUserIsSuperUser();
-        Piwik::createLogObject();
+        \Piwik\Log::make();
     }
 
     /**
@@ -552,7 +561,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
     {
         $language = Common::getRequestVar('language');
         Piwik_LanguagesManager::setLanguageForSession($language);
-        Piwik_Url::redirectToReferer();
+        Url::redirectToReferer();
     }
 
     /**
@@ -594,7 +603,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
             $message = Piwik_Translate('Installation_ErrorInvalidState',
                 array('<br /><b>',
                       '</b>',
-                      '<a href=\'' . Common::sanitizeInputValue(Piwik_Url::getCurrentUrlWithoutFileName()) . '\'>',
+                      '<a href=\'' . Common::sanitizeInputValue(Url::getCurrentUrlWithoutFileName()) . '\'>',
                       '</a>')
             );
             Piwik::exitWithErrorMessage($message);
@@ -653,7 +662,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
         $trustedHosts = array();
 
         // extract host from the request header
-        if (($host = $this->extractHost('http://' . Piwik_Url::getHost())) !== false) {
+        if (($host = $this->extractHost('http://' . Url::getHost())) !== false) {
             $trustedHosts[] = $host;
         }
 
@@ -733,7 +742,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
             $infos['pdo_ok'] = true;
         }
 
-        $infos['adapters'] = Piwik_Db_Adapter::getAdapters();
+        $infos['adapters'] = Adapter::getAdapters();
 
         $needed_functions = array(
             'debug_backtrace',
@@ -780,7 +789,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
             }
         }
 
-        $infos['openurl'] = Piwik_Http::getTransportMethod();
+        $infos['openurl'] = Http::getTransportMethod();
 
         $infos['gd_ok'] = Piwik::isGdExtensionEnabled();
 
@@ -827,14 +836,14 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
 
         $infos['tracker_status'] = Common::getRequestVar('trackerStatus', 0, 'int');
 
-        $infos['protocol'] = Piwik_ProxyHeaders::getProtocolInformation();
+        $infos['protocol'] = ProxyHeaders::getProtocolInformation();
         if (!Piwik::isHttps() && $infos['protocol'] !== null) {
             $infos['general_infos']['assume_secure_protocol'] = '1';
         }
-        if (count($headers = Piwik_ProxyHeaders::getProxyClientHeaders()) > 0) {
+        if (count($headers = ProxyHeaders::getProxyClientHeaders()) > 0) {
             $infos['general_infos']['proxy_client_headers'] = $headers;
         }
-        if (count($headers = Piwik_ProxyHeaders::getProxyHostHeaders()) > 0) {
+        if (count($headers = ProxyHeaders::getProxyHostHeaders()) > 0) {
             $infos['general_infos']['proxy_host_headers'] = $headers;
         }
 
@@ -902,7 +911,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
     /**
      * Utility function, sets up a view that will display system check info.
      *
-     * @param Piwik_View $view
+     * @param View $view
      */
     private function setupSystemCheckView($view)
     {
@@ -967,7 +976,7 @@ class Piwik_Installation_Controller extends Piwik_Controller_Admin
         }
 
         // delete the temporary rows that were created
-        Piwik_Exec("DELETE FROM `$optionTable` WHERE option_name IN ('" . implode("','", $testOptionNames) . "')");
+        Db::exec("DELETE FROM `$optionTable` WHERE option_name IN ('" . implode("','", $testOptionNames) . "')");
 
         return $result;
     }
diff --git a/plugins/Installation/FormDatabaseSetup.php b/plugins/Installation/FormDatabaseSetup.php
index d10f3b5a49..8939ace24e 100644
--- a/plugins/Installation/FormDatabaseSetup.php
+++ b/plugins/Installation/FormDatabaseSetup.php
@@ -8,14 +8,16 @@
  * @category Piwik_Plugins
  * @package Piwik_Installation
  */
+use Piwik\Db\Adapter;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\QuickForm2;
 
 /**
  *
  * @package Piwik_Installation
  */
-class Piwik_Installation_FormDatabaseSetup extends Piwik_QuickForm2
+class Piwik_Installation_FormDatabaseSetup extends QuickForm2
 {
     function __construct($id = 'databasesetupform', $method = 'post', $attributes = null, $trackSubmit = false)
     {
@@ -29,7 +31,7 @@ class Piwik_Installation_FormDatabaseSetup extends Piwik_QuickForm2
         $checkUserPrivilegesClass = 'Piwik_Installation_FormDatabaseSetup_Rule_checkUserPrivileges';
         HTML_QuickForm2_Factory::registerRule('checkUserPrivileges', $checkUserPrivilegesClass);
 
-        $availableAdapters = Piwik_Db_Adapter::getAdapters();
+        $availableAdapters = Adapter::getAdapters();
         $adapters = array();
         foreach ($availableAdapters as $adapter => $port) {
             $adapters[$adapter] = $adapter;
@@ -88,7 +90,7 @@ class Piwik_Installation_FormDatabaseSetup extends Piwik_QuickForm2
         }
 
         $adapter = $this->getSubmitValue('adapter');
-        $port = Piwik_Db_Adapter::getDefaultPortForAdapter($adapter);
+        $port = Adapter::getDefaultPortForAdapter($adapter);
 
         $dbInfos = array(
             'host'          => $this->getSubmitValue('host'),
@@ -113,7 +115,7 @@ class Piwik_Installation_FormDatabaseSetup extends Piwik_QuickForm2
         try {
             @Piwik::createDatabaseObject($dbInfos);
         } catch (Zend_Db_Adapter_Exception $e) {
-            $db = Piwik_Db_Adapter::factory($adapter, $dbInfos, $connect = false);
+            $db = Adapter::factory($adapter, $dbInfos, $connect = false);
 
             // database not found, we try to create  it
             if ($db->isErrNo($e, '1049')) {
diff --git a/plugins/Installation/FormFirstWebsiteSetup.php b/plugins/Installation/FormFirstWebsiteSetup.php
index d44151f1b5..31c3e4cf4a 100644
--- a/plugins/Installation/FormFirstWebsiteSetup.php
+++ b/plugins/Installation/FormFirstWebsiteSetup.php
@@ -8,12 +8,13 @@
  * @category Piwik_Plugins
  * @package Piwik_Installation
  */
+use Piwik\QuickForm2;
 
 /**
  *
  * @package Piwik_Installation
  */
-class Piwik_Installation_FormFirstWebsiteSetup extends Piwik_QuickForm2
+class Piwik_Installation_FormFirstWebsiteSetup extends QuickForm2
 {
     function __construct($id = 'websitesetupform', $method = 'post', $attributes = null, $trackSubmit = false)
     {
diff --git a/plugins/Installation/FormGeneralSetup.php b/plugins/Installation/FormGeneralSetup.php
index 23f1dbce94..bd2504588a 100644
--- a/plugins/Installation/FormGeneralSetup.php
+++ b/plugins/Installation/FormGeneralSetup.php
@@ -9,12 +9,13 @@
  * @package Piwik_Installation
  */
 use Piwik\Piwik;
+use Piwik\QuickForm2;
 
 /**
  *
  * @package Piwik_Installation
  */
-class Piwik_Installation_FormGeneralSetup extends Piwik_QuickForm2
+class Piwik_Installation_FormGeneralSetup extends QuickForm2
 {
     function __construct($id = 'generalsetupform', $method = 'post', $attributes = null, $trackSubmit = false)
     {
diff --git a/plugins/Installation/View.php b/plugins/Installation/View.php
index e2db289eb1..84a8d631cf 100644
--- a/plugins/Installation/View.php
+++ b/plugins/Installation/View.php
@@ -8,12 +8,13 @@
  * @category Piwik_Plugins
  * @package Piwik_Installation
  */
+use Piwik\View;
 
 /**
  *
  * @package Piwik_Installation
  */
-class Piwik_Installation_View extends Piwik_View
+class Piwik_Installation_View extends View
 {
     public function __construct($subtemplatePath, $installationSteps, $currentStepName)
     {
diff --git a/plugins/LanguagesManager/API.php b/plugins/LanguagesManager/API.php
index bda2419908..d42d5cdfc4 100644
--- a/plugins/LanguagesManager/API.php
+++ b/plugins/LanguagesManager/API.php
@@ -161,7 +161,7 @@ class Piwik_LanguagesManager_API
     {
         Piwik::checkUserIsSuperUserOrTheUser($login);
         Piwik::checkUserIsNotAnonymous();
-        return Piwik_FetchOne('SELECT language FROM ' . Common::prefixTable('user_language') .
+        return Db::fetchOne('SELECT language FROM ' . Common::prefixTable('user_language') .
             ' WHERE login = ? ', array($login));
     }
 
@@ -180,7 +180,7 @@ class Piwik_LanguagesManager_API
             return false;
         }
         $paramsBind = array($login, $languageCode, $languageCode);
-        Piwik_Query('INSERT INTO ' . Common::prefixTable('user_language') .
+        Db::query('INSERT INTO ' . Common::prefixTable('user_language') .
                 ' (login, language)
                     VALUES (?,?)
                 ON DUPLICATE KEY UPDATE language=?',
diff --git a/plugins/LanguagesManager/Controller.php b/plugins/LanguagesManager/Controller.php
index 6685b511e4..212293ce79 100644
--- a/plugins/LanguagesManager/Controller.php
+++ b/plugins/LanguagesManager/Controller.php
@@ -11,11 +11,13 @@
  */
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\Url;
 
 /**
  * @package Piwik_LanguagesManager
  */
-class Piwik_LanguagesManager_Controller extends Piwik_Controller
+class Piwik_LanguagesManager_Controller extends Controller
 {
     /**
      * anonymous = in the session
@@ -36,6 +38,6 @@ class Piwik_LanguagesManager_Controller extends Piwik_Controller
                 Piwik_LanguagesManager_API::getInstance()->setLanguageForUser($currentUser, $language);
             }
         }
-        Piwik_Url::redirectToReferer();
+        Url::redirectToReferer();
     }
 }
diff --git a/plugins/LanguagesManager/LanguagesManager.php b/plugins/LanguagesManager/LanguagesManager.php
index 1d0bc24ed9..5b848784bd 100644
--- a/plugins/LanguagesManager/LanguagesManager.php
+++ b/plugins/LanguagesManager/LanguagesManager.php
@@ -12,6 +12,8 @@
 use Piwik\Config;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Cookie;
+use Piwik\View;
 use Piwik\Plugin;
 use Piwik\Translate;
 
@@ -71,7 +73,7 @@ class Piwik_LanguagesManager extends Plugin
      */
     private function getLanguagesSelector()
     {
-        $view = new Piwik_View("@LanguagesManager/getLanguagesSelector");
+        $view = new View("@LanguagesManager/getLanguagesSelector");
         $view->languages = Piwik_LanguagesManager_API::getInstance()->getAvailableLanguageNames();
         $view->currentLanguageCode = self::getLanguageCodeForCurrentUser();
         $view->currentLanguageName = self::getLanguageNameForCurrentUser();
@@ -90,7 +92,7 @@ class Piwik_LanguagesManager extends Plugin
 
     public function deleteUserLanguage($userLogin)
     {
-        Piwik_Query('DELETE FROM ' . Common::prefixTable('user_language') . ' WHERE login = ?', $userLogin);
+        Db::query('DELETE FROM ' . Common::prefixTable('user_language') . ' WHERE login = ?', $userLogin);
     }
 
     /**
@@ -105,7 +107,7 @@ class Piwik_LanguagesManager extends Plugin
 					language VARCHAR( 10 ) NOT NULL ,
 					PRIMARY KEY ( login )
 					)  DEFAULT CHARSET=utf8 ";
-            Piwik_Exec($sql);
+            Db::exec($sql);
         } catch (Exception $e) {
             // mysql code error 1050:table already exists
             // see bug #153 http://dev.piwik.org/trac/ticket/153
@@ -120,7 +122,7 @@ class Piwik_LanguagesManager extends Plugin
      */
     public function uninstall()
     {
-        Piwik_DropTables(Common::prefixTable('user_language'));
+        Db::dropTables(Common::prefixTable('user_language'));
     }
 
     /**
@@ -178,7 +180,7 @@ class Piwik_LanguagesManager extends Plugin
     static public function getLanguageForSession()
     {
         $cookieName = Config::getInstance()->General['language_cookie_name'];
-        $cookie = new Piwik_Cookie($cookieName);
+        $cookie = new Cookie($cookieName);
         if ($cookie->isCookieFound()) {
             return $cookie->get('language');
         }
@@ -198,7 +200,7 @@ class Piwik_LanguagesManager extends Plugin
         }
 
         $cookieName = Config::getInstance()->General['language_cookie_name'];
-        $cookie = new Piwik_Cookie($cookieName, 0);
+        $cookie = new Cookie($cookieName, 0);
         $cookie->set('language', $languageCode);
         $cookie->save();
     }
diff --git a/plugins/Live/API.php b/plugins/Live/API.php
index 8a739a0b17..4fd3ab3b91 100644
--- a/plugins/Live/API.php
+++ b/plugins/Live/API.php
@@ -18,6 +18,7 @@ use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Date;
 use Piwik\DataTable;
+use Piwik\Tracker;
 use Piwik\Segment;
 use Piwik\Site;
 
@@ -93,7 +94,7 @@ class Piwik_Live_API
         $segment = new Segment($segment, $idSite);
         $query = $segment->getSelectQuery($select, $from, $where, $bind);
 
-        $data = Piwik_FetchAll($query['sql'], $query['bind']);
+        $data = Db::fetchAll($query['sql'], $query['bind']);
 
         // These could be unset for some reasons, ensure they are set to 0
         if (empty($data[0]['actions'])) {
@@ -416,7 +417,7 @@ class Piwik_Live_API
 			ORDER BY $orderByParent
 		";
         try {
-            $data = Piwik_FetchAll($sql, $subQuery['bind']);
+            $data = Db::fetchAll($sql, $subQuery['bind']);
         } catch (Exception $e) {
             echo $e->getMessage();
             exit;
@@ -458,7 +459,7 @@ class Piwik_Live_API
         $idVisit = $visitorDetailsArray['idVisit'];
 
         $sqlCustomVariables = '';
-        for ($i = 1; $i <= Piwik_Tracker::MAX_CUSTOM_VARIABLES; $i++) {
+        for ($i = 1; $i <= Tracker::MAX_CUSTOM_VARIABLES; $i++) {
             $sqlCustomVariables .= ', custom_var_k' . $i . ', custom_var_v' . $i;
         }
         // The second join is a LEFT join to allow returning records that don't have a matching page title
@@ -484,12 +485,12 @@ class Piwik_Live_API
 				ORDER BY server_time ASC
 				LIMIT 0, $actionsLimit
 				 ";
-        $actionDetails = Piwik_FetchAll($sql, array($idVisit));
+        $actionDetails = Db::fetchAll($sql, array($idVisit));
 
         foreach ($actionDetails as $actionIdx => &$actionDetail) {
             $actionDetail =& $actionDetails[$actionIdx];
             $customVariablesPage = array();
-            for ($i = 1; $i <= Piwik_Tracker::MAX_CUSTOM_VARIABLES; $i++) {
+            for ($i = 1; $i <= Tracker::MAX_CUSTOM_VARIABLES; $i++) {
                 if (!empty($actionDetail['custom_var_k' . $i])) {
                     $cvarKey = $actionDetail['custom_var_k' . $i];
                     $cvarKey = $this->getCustomVariablePrettyKey($cvarKey);
@@ -551,7 +552,7 @@ class Piwik_Live_API
                 ORDER BY server_time ASC
 				LIMIT 0, $actionsLimit
 			";
-        $goalDetails = Piwik_FetchAll($sql, array($idVisit));
+        $goalDetails = Db::fetchAll($sql, array($idVisit));
 
         $sql = "SELECT
 						case idgoal when " . Piwik_Tracker_GoalManager::IDGOAL_CART . " then '" . Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_CART . "' else '" . Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_ORDER . "' end as type,
@@ -569,7 +570,7 @@ class Piwik_Live_API
 						AND idgoal <= " . Piwik_Tracker_GoalManager::IDGOAL_ORDER . "
 					ORDER BY server_time ASC
 					LIMIT 0, $actionsLimit";
-        $ecommerceDetails = Piwik_FetchAll($sql, array($idVisit));
+        $ecommerceDetails = Db::fetchAll($sql, array($idVisit));
 
         foreach ($ecommerceDetails as &$ecommerceDetail) {
             if ($ecommerceDetail['type'] == Piwik::LABEL_ID_GOAL_IS_ECOMMERCE_CART) {
@@ -616,7 +617,7 @@ class Piwik_Live_API
                 : Piwik_Tracker_GoalManager::ITEM_IDORDER_ABANDONED_CART
             );
 
-            $itemsDetails = Piwik_FetchAll($sql, $bind);
+            $itemsDetails = Db::fetchAll($sql, $bind);
             foreach ($itemsDetails as &$detail) {
                 if ($detail['price'] == round($detail['price'])) {
                     $detail['price'] = round($detail['price']);
diff --git a/plugins/Live/Controller.php b/plugins/Live/Controller.php
index 69c94fdf87..0420f85615 100644
--- a/plugins/Live/Controller.php
+++ b/plugins/Live/Controller.php
@@ -8,14 +8,18 @@
  * @category Piwik_Plugins
  * @package Piwik_Live
  */
+use Piwik\API\Request;
 use Piwik\Common;
 use Piwik\Piwik;
 use Piwik\Config;
+use Piwik\Controller;
+use Piwik\ViewDataTable;
+use Piwik\View;
 
 /**
  * @package Piwik_Live
  */
-class Piwik_Live_Controller extends Piwik_Controller
+class Piwik_Live_Controller extends Controller
 {
     const SIMPLE_VISIT_COUNT_WIDGET_LAST_MINUTES_CONFIG_KEY = 'live_widget_visitor_count_last_minutes';
 
@@ -26,7 +30,7 @@ class Piwik_Live_Controller extends Piwik_Controller
 
     public function widget($fetch = false)
     {
-        $view = new Piwik_View('@Live/index');
+        $view = new View('@Live/index');
         $view->idSite = $this->idSite;
         $view = $this->setCounters($view);
         $view->liveRefreshAfterMs = (int)Config::getInstance()->General['live_widget_refresh_after_seconds'] * 1000;
@@ -39,9 +43,9 @@ class Piwik_Live_Controller extends Piwik_Controller
     {
         $lastMinutes = Config::getInstance()->General[self::SIMPLE_VISIT_COUNT_WIDGET_LAST_MINUTES_CONFIG_KEY];
 
-        $lastNData = Piwik_API_Request::processRequest('Live.getCounters', array('lastMinutes' => $lastMinutes));
+        $lastNData = Request::processRequest('Live.getCounters', array('lastMinutes' => $lastMinutes));
 
-        $view = new Piwik_View('@Live/getSimpleLastVisitCount');
+        $view = new View('@Live/getSimpleLastVisitCount');
         $view->lastMinutes = $lastMinutes;
         $view->visitors = Piwik::getPrettyNumber($lastNData[0]['visitors']);
         $view->visits = Piwik::getPrettyNumber($lastNData[0]['visits']);
@@ -62,13 +66,13 @@ class Piwik_Live_Controller extends Piwik_Controller
 
     public function ajaxTotalVisitors($fetch = false)
     {
-        $view = new Piwik_View('@Live/ajaxTotalVisitors');
+        $view = new View('@Live/ajaxTotalVisitors');
         $view = $this->setCounters($view);
         $view->idSite = $this->idSite;
         return $this->render($view, $fetch);
     }
 
-    private function render(Piwik_View $view, $fetch)
+    private function render(View $view, $fetch)
     {
         $rendered = $view->render();
         if ($fetch) {
@@ -79,7 +83,7 @@ class Piwik_Live_Controller extends Piwik_Controller
     
     public function indexVisitorLog()
     {
-        $view = new Piwik_View('@Live/indexVisitorLog.twig');
+        $view = new View('@Live/indexVisitorLog.twig');
         $view->filterEcommerce = Common::getRequestVar('filterEcommerce', 0, 'int');
         $view->visitorLog = $this->getVisitorLog($fetch = true);
         echo $view->render();
@@ -87,7 +91,7 @@ class Piwik_Live_Controller extends Piwik_Controller
 
     public function getVisitorLog($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName,
             __FUNCTION__,
             'Live.getLastVisitsDetails'
@@ -129,10 +133,10 @@ class Piwik_Live_Controller extends Piwik_Controller
         // hack, ensure we load today's visits by default
         $_GET['date'] = 'today';
         $_GET['period'] = 'day';
-        $view = new Piwik_View('@Live/getLastVisitsStart');
+        $view = new View('@Live/getLastVisitsStart');
         $view->idSite = $this->idSite;
 
-        $api = new Piwik_API_Request("method=Live.getLastVisitsDetails&idSite={$this->idSite}&filter_limit=10&format=php&serialize=0&disable_generic_filters=1");
+        $api = new Request("method=Live.getLastVisitsDetails&idSite={$this->idSite}&filter_limit=10&format=php&serialize=0&disable_generic_filters=1");
         $visitors = $api->process();
         $view->visitors = $visitors;
 
@@ -141,7 +145,7 @@ class Piwik_Live_Controller extends Piwik_Controller
 
     private function setCounters($view)
     {
-        $segment = Piwik_ViewDataTable::getRawSegmentFromRequest();
+        $segment = ViewDataTable::getRawSegmentFromRequest();
         $last30min = Piwik_Live_API::getInstance()->getCounters($this->idSite, $lastMinutes = 30, $segment);
         $last30min = $last30min[0];
         $today = Piwik_Live_API::getInstance()->getCounters($this->idSite, $lastMinutes = 24 * 60, $segment);
diff --git a/plugins/Live/Live.php b/plugins/Live/Live.php
index ba6bf5b219..4cd54520ef 100644
--- a/plugins/Live/Live.php
+++ b/plugins/Live/Live.php
@@ -46,9 +46,9 @@ class Piwik_Live extends Plugin
 
     public function addWidget()
     {
-        Piwik_AddWidget('Live!', 'Live_VisitorsInRealTime', 'Live', 'widget');
-        Piwik_AddWidget('Live!', 'Live_VisitorLog', 'Live', 'getVisitorLog');
-        Piwik_AddWidget('Live!', 'Live_RealTimeVisitorCount', 'Live', 'getSimpleLastVisitCount');
+        WidgetsList::add('Live!', 'Live_VisitorsInRealTime', 'Live', 'widget');
+        WidgetsList::add('Live!', 'Live_VisitorLog', 'Live', 'getVisitorLog');
+        WidgetsList::add('Live!', 'Live_RealTimeVisitorCount', 'Live', 'getSimpleLastVisitCount');
     }
 
 }
diff --git a/plugins/Live/Visitor.php b/plugins/Live/Visitor.php
index df7edf761d..db31fe886f 100644
--- a/plugins/Live/Visitor.php
+++ b/plugins/Live/Visitor.php
@@ -10,6 +10,8 @@
  */
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\IP;
+use Piwik\Tracker;
 
 /**
  * @see plugins/Referers/functions.php
@@ -168,7 +170,7 @@ class Piwik_Live_Visitor
     function getIp()
     {
         if (isset($this->details['location_ip'])) {
-            return Piwik_IP::N2P($this->details['location_ip']);
+            return IP::N2P($this->details['location_ip']);
         }
         return false;
     }
@@ -319,7 +321,7 @@ class Piwik_Live_Visitor
     function getCustomVariables()
     {
         $customVariables = array();
-        for ($i = 1; $i <= Piwik_Tracker::MAX_CUSTOM_VARIABLES; $i++) {
+        for ($i = 1; $i <= Tracker::MAX_CUSTOM_VARIABLES; $i++) {
             if (!empty($this->details['custom_var_k' . $i])) {
                 $customVariables[$i] = array(
                     'customVariableName' . $i  => $this->details['custom_var_k' . $i],
diff --git a/plugins/Login/Auth.php b/plugins/Login/Auth.php
index 1f643b2843..4280321be3 100644
--- a/plugins/Login/Auth.php
+++ b/plugins/Login/Auth.php
@@ -48,7 +48,7 @@ class Piwik_Login_Auth implements Auth
                 return new AuthResult(AuthResult::SUCCESS_SUPERUSER_AUTH_CODE, $rootLogin, $this->token_auth);
             }
 
-            $login = Piwik_FetchOne(
+            $login = Db::fetchOne(
                 'SELECT login
                 FROM ' . Common::prefixTable('user') . '
 					WHERE token_auth = ?',
@@ -67,7 +67,7 @@ class Piwik_Login_Auth implements Auth
             }
 
             $login = $this->login;
-            $userToken = Piwik_FetchOne(
+            $userToken = Db::fetchOne(
                 'SELECT token_auth
                 FROM ' . Common::prefixTable('user') . '
 					WHERE login = ?',
diff --git a/plugins/Login/Controller.php b/plugins/Login/Controller.php
index 28aa0e285c..4aebcd3a86 100644
--- a/plugins/Login/Controller.php
+++ b/plugins/Login/Controller.php
@@ -11,6 +11,15 @@
 use Piwik\Config;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\Cookie;
+use Piwik\IP;
+use Piwik\Mail;
+use Piwik\Nonce;
+use Piwik\View;
+use Piwik\Url;
+use Piwik\QuickForm2;
+use Piwik\Session;
 
 require_once PIWIK_INCLUDE_PATH . '/core/Config.php';
 
@@ -19,7 +28,7 @@ require_once PIWIK_INCLUDE_PATH . '/core/Config.php';
  *
  * @package Piwik_Login
  */
-class Piwik_Login_Controller extends Piwik_Controller
+class Piwik_Login_Controller extends Controller
 {
     /**
      * Generate hash on user info and password
@@ -65,7 +74,7 @@ class Piwik_Login_Controller extends Piwik_Controller
         $form = new Piwik_Login_FormLogin();
         if ($form->validate()) {
             $nonce = $form->getSubmitValue('form_nonce');
-            if (Piwik_Nonce::verifyNonce('Piwik_Login.login', $nonce)) {
+            if (Nonce::verifyNonce('Piwik_Login.login', $nonce)) {
                 $login = $form->getSubmitValue('form_login');
                 $password = $form->getSubmitValue('form_password');
                 $rememberMe = $form->getSubmitValue('form_rememberme') == '1';
@@ -80,7 +89,7 @@ class Piwik_Login_Controller extends Piwik_Controller
             }
         }
 
-        $view = new Piwik_View('@Login/login');
+        $view = new View('@Login/login');
         $view->AccessErrorString = $messageNoAccess;
         $view->infoMessage = nl2br($infoMessage);
         $view->addForm($form);
@@ -92,7 +101,7 @@ class Piwik_Login_Controller extends Piwik_Controller
     /**
      * Configure common view properties
      *
-     * @param Piwik_View $view
+     * @param View $view
      */
     private function configureView($view)
     {
@@ -103,7 +112,7 @@ class Piwik_Login_Controller extends Piwik_Controller
         $view->forceSslLogin = Config::getInstance()->General['force_ssl_login'];
 
         // crsf token: don't trust the submitted value; generate/fetch it from session data
-        $view->nonce = Piwik_Nonce::getNonce('Piwik_Login.login');
+        $view->nonce = Nonce::getNonce('Piwik_Login.login');
     }
 
     /**
@@ -153,9 +162,9 @@ class Piwik_Login_Controller extends Piwik_Controller
                       'md5Password' => $md5Password,
                       'rememberMe'  => $rememberMe,
         );
-        Piwik_Nonce::discardNonce('Piwik_Login.login');
+        Nonce::discardNonce('Piwik_Login.login');
         Piwik_PostEvent('Login.initSession', array(&$info));
-        Piwik_Url::redirectToUrl($urlToRedirect);
+        Url::redirectToUrl($urlToRedirect);
     }
 
     protected function getMessageExceptionNoAccess()
@@ -182,7 +191,7 @@ class Piwik_Login_Controller extends Piwik_Controller
         $form = new Piwik_Login_FormResetPassword();
         if ($form->validate()) {
             $nonce = $form->getSubmitValue('form_nonce');
-            if (Piwik_Nonce::verifyNonce('Piwik_Login.login', $nonce)) {
+            if (Nonce::verifyNonce('Piwik_Login.login', $nonce)) {
                 $formErrors = $this->resetPasswordFirstStep($form);
                 if (empty($formErrors)) {
                     $infoMessage = Piwik_Translate('Login_ConfirmationLinkSent');
@@ -196,7 +205,7 @@ class Piwik_Login_Controller extends Piwik_Controller
             $formErrors = $formData['errors'];
         }
 
-        $view = new Piwik_View('@Login/resetPassword');
+        $view = new View('@Login/resetPassword');
         $view->infoMessage = $infoMessage;
         $view->formErrors = $formErrors;
         echo $view->render();
@@ -205,7 +214,7 @@ class Piwik_Login_Controller extends Piwik_Controller
     /**
      * Saves password reset info and sends confirmation email.
      *
-     * @param Piwik_QuickForm2 $form
+     * @param QuickForm2 $form
      * @return array Error message(s) if an error occurs.
      */
     private function resetPasswordFirstStep($form)
@@ -262,13 +271,13 @@ class Piwik_Login_Controller extends Piwik_Controller
         // construct a password reset token from user information
         $resetToken = self::generatePasswordResetToken($user);
 
-        $ip = Piwik_IP::getIpFromHeader();
-        $url = Piwik_Url::getCurrentUrlWithoutQueryString()
+        $ip = IP::getIpFromHeader();
+        $url = Url::getCurrentUrlWithoutQueryString()
             . "?module=Login&action=confirmResetPassword&login=" . urlencode($login)
             . "&resetToken=" . urlencode($resetToken);
 
         // send email with new password
-        $mail = new Piwik_Mail();
+        $mail = new Mail();
         $mail->addTo($email, $login);
         $mail->setSubject(Piwik_Translate('Login_MailTopicPasswordChange'));
         $bodyText = str_replace(
@@ -447,10 +456,10 @@ class Piwik_Login_Controller extends Piwik_Controller
     static public function clearSession()
     {
         $authCookieName = Config::getInstance()->General['login_cookie_name'];
-        $cookie = new Piwik_Cookie($authCookieName);
+        $cookie = new Cookie($authCookieName);
         $cookie->delete();
 
-        Piwik_Session::expireSessionCookie();
+        Session::expireSessionCookie();
     }
 
     /**
@@ -467,7 +476,7 @@ class Piwik_Login_Controller extends Piwik_Controller
         if (empty($logoutUrl)) {
             Piwik::redirectToModule('CoreHome');
         } else {
-            Piwik_Url::redirectToUrl($logoutUrl);
+            Url::redirectToUrl($logoutUrl);
         }
     }
 
@@ -484,10 +493,10 @@ class Piwik_Login_Controller extends Piwik_Controller
             && !Piwik::isHttps()
         ) {
             $url = 'https://'
-                . Piwik_Url::getCurrentHost()
-                . Piwik_Url::getCurrentScriptName()
-                . Piwik_Url::getCurrentQueryString();
-            Piwik_Url::redirectToUrl($url);
+                . Url::getCurrentHost()
+                . Url::getCurrentScriptName()
+                . Url::getCurrentQueryString();
+            Url::redirectToUrl($url);
         }
     }
 }
diff --git a/plugins/Login/FormLogin.php b/plugins/Login/FormLogin.php
index a90146f47e..229288e713 100644
--- a/plugins/Login/FormLogin.php
+++ b/plugins/Login/FormLogin.php
@@ -8,12 +8,13 @@
  * @category Piwik_Plugins
  * @package Piwik_Login
  */
+use Piwik\QuickForm2;
 
 /**
  *
  * @package Piwik_Login
  */
-class Piwik_Login_FormLogin extends Piwik_QuickForm2
+class Piwik_Login_FormLogin extends QuickForm2
 {
     function __construct($id = 'login_form', $method = 'post', $attributes = null, $trackSubmit = false)
     {
diff --git a/plugins/Login/FormResetPassword.php b/plugins/Login/FormResetPassword.php
index 0411beddbb..abbe1bd4a1 100644
--- a/plugins/Login/FormResetPassword.php
+++ b/plugins/Login/FormResetPassword.php
@@ -8,12 +8,13 @@
  * @category Piwik_Plugins
  * @package Piwik_Login
  */
+use Piwik\QuickForm2;
 
 /**
  *
  * @package Piwik_Login
  */
-class Piwik_Login_FormResetPassword extends Piwik_QuickForm2
+class Piwik_Login_FormResetPassword extends QuickForm2
 {
     function __construct($id = 'resetpasswordform', $method = 'post', $attributes = null, $trackSubmit = false)
     {
diff --git a/plugins/Login/Login.php b/plugins/Login/Login.php
index 7208328074..b8718f93d5 100644
--- a/plugins/Login/Login.php
+++ b/plugins/Login/Login.php
@@ -10,6 +10,9 @@
  */
 use Piwik\Config;
 use Piwik\Piwik;
+use Piwik\Cookie;
+use Piwik\Piwik_Option;
+use Piwik\Session;
 use Piwik\Plugin;
 
 /**
@@ -74,7 +77,7 @@ class Piwik_Login extends Plugin
         $authCookieName = Config::getInstance()->General['login_cookie_name'];
         $authCookieExpiry = 0;
         $authCookiePath = Config::getInstance()->General['login_cookie_path'];
-        $authCookie = new Piwik_Cookie($authCookieName, $authCookieExpiry, $authCookiePath);
+        $authCookie = new Cookie($authCookieName, $authCookieExpiry, $authCookiePath);
         $defaultLogin = 'anonymous';
         $defaultTokenAuth = 'anonymous';
         if ($authCookie->isCookieFound()) {
@@ -107,7 +110,7 @@ class Piwik_Login extends Plugin
         $authCookieName = Config::getInstance()->General['login_cookie_name'];
         $authCookieExpiry = $rememberMe ? time() + Config::getInstance()->General['login_cookie_expire'] : 0;
         $authCookiePath = Config::getInstance()->General['login_cookie_path'];
-        $cookie = new Piwik_Cookie($authCookieName, $authCookieExpiry, $authCookiePath);
+        $cookie = new Cookie($authCookieName, $authCookieExpiry, $authCookiePath);
         if (!$authResult->isValid()) {
             $cookie->delete();
             throw new Exception(Piwik_Translate('Login_LoginPasswordNotCorrect'));
@@ -119,7 +122,7 @@ class Piwik_Login extends Plugin
         $cookie->setHttpOnly(true);
         $cookie->save();
 
-        @Piwik_Session::regenerateId();
+        @Session::regenerateId();
 
         // remove password reset entry if it exists
         self::removePasswordResetInfo($login);
diff --git a/plugins/MobileMessaging/Controller.php b/plugins/MobileMessaging/Controller.php
index a97641ed0c..0054d62912 100644
--- a/plugins/MobileMessaging/Controller.php
+++ b/plugins/MobileMessaging/Controller.php
@@ -9,8 +9,11 @@
  * @package Piwik_MobileMessaging
  */
 
+use Piwik\Controller\Admin;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\IP;
+use Piwik\View;
 
 require_once PIWIK_INCLUDE_PATH . '/plugins/UserCountry/functions.php';
 
@@ -18,7 +21,7 @@ require_once PIWIK_INCLUDE_PATH . '/plugins/UserCountry/functions.php';
  *
  * @package Piwik_MobileMessaging
  */
-class Piwik_MobileMessaging_Controller extends Piwik_Controller_Admin
+class Piwik_MobileMessaging_Controller extends Admin
 {
     /*
      * Mobile Messaging Settings tab :
@@ -31,7 +34,7 @@ class Piwik_MobileMessaging_Controller extends Piwik_Controller_Admin
     {
         Piwik::checkUserIsNotAnonymous();
 
-        $view = new Piwik_View('@MobileMessaging/index');
+        $view = new View('@MobileMessaging/index');
 
         $view->isSuperUser = Piwik::isUserIsSuperUser();
 
@@ -63,7 +66,7 @@ class Piwik_MobileMessaging_Controller extends Piwik_Controller_Admin
         $view->defaultCountry = Common::getCountry(
             Piwik_LanguagesManager::getLanguageCodeForCurrentUser(),
             true,
-            Piwik_IP::getIpFromHeader()
+            IP::getIpFromHeader()
         );
 
         $view->phoneNumbers = $mobileMessagingAPI->getPhoneNumbers();
diff --git a/plugins/MobileMessaging/MobileMessaging.php b/plugins/MobileMessaging/MobileMessaging.php
index 840ae48abc..532e511d73 100644
--- a/plugins/MobileMessaging/MobileMessaging.php
+++ b/plugins/MobileMessaging/MobileMessaging.php
@@ -9,6 +9,7 @@
  * @package Piwik_MobileMessaging
  */
 use Piwik\Piwik;
+use Piwik\View;
 use Piwik\Plugin;
 
 /**
@@ -216,7 +217,7 @@ class Piwik_MobileMessaging extends Plugin
             return;
         }
 
-        $view = new Piwik_View('@MobileMessaging/reportParametersPDFReports');
+        $view = new View('@MobileMessaging/reportParametersPDFReports');
         $view->reportType = self::MOBILE_TYPE;
         $view->phoneNumbers = Piwik_MobileMessaging_API::getInstance()->getActivatedPhoneNumbers();
         $out .= $view->render();
diff --git a/plugins/MobileMessaging/ReportRenderer/Exception.php b/plugins/MobileMessaging/ReportRenderer/Exception.php
index c6cdacf36b..cc5b137a38 100644
--- a/plugins/MobileMessaging/ReportRenderer/Exception.php
+++ b/plugins/MobileMessaging/ReportRenderer/Exception.php
@@ -8,12 +8,13 @@
  * @category Piwik_Plugins
  * @package Piwik_MobileMessaging_ReportRenderer
  */
+use Piwik\ReportRenderer;
 
 /**
  *
  * @package Piwik_MobileMessaging_ReportRenderer
  */
-class Piwik_MobileMessaging_ReportRenderer_Exception extends Piwik_ReportRenderer
+class Piwik_MobileMessaging_ReportRenderer_Exception extends ReportRenderer
 {
     private $rendering = "";
 
@@ -29,7 +30,7 @@ class Piwik_MobileMessaging_ReportRenderer_Exception extends Piwik_ReportRendere
 
     public function sendToDisk($filename)
     {
-        return Piwik_ReportRenderer::writeFile(
+        return ReportRenderer::writeFile(
             $filename,
             Piwik_MobileMessaging_ReportRenderer_Sms::SMS_FILE_EXTENSION,
             $this->rendering
@@ -38,7 +39,7 @@ class Piwik_MobileMessaging_ReportRenderer_Exception extends Piwik_ReportRendere
 
     public function sendToBrowserDownload($filename)
     {
-        Piwik_ReportRenderer::sendToBrowser(
+        ReportRenderer::sendToBrowser(
             $filename,
             Piwik_MobileMessaging_ReportRenderer_Sms::SMS_FILE_EXTENSION,
             Piwik_MobileMessaging_ReportRenderer_Sms::SMS_CONTENT_TYPE,
@@ -48,7 +49,7 @@ class Piwik_MobileMessaging_ReportRenderer_Exception extends Piwik_ReportRendere
 
     public function sendToBrowserInline($filename)
     {
-        Piwik_ReportRenderer::inlineToBrowser(
+        ReportRenderer::inlineToBrowser(
             Piwik_MobileMessaging_ReportRenderer_Sms::SMS_CONTENT_TYPE,
             $this->rendering
         );
diff --git a/plugins/MobileMessaging/ReportRenderer/Sms.php b/plugins/MobileMessaging/ReportRenderer/Sms.php
index 68bc22691a..5c89166ea2 100644
--- a/plugins/MobileMessaging/ReportRenderer/Sms.php
+++ b/plugins/MobileMessaging/ReportRenderer/Sms.php
@@ -9,13 +9,15 @@
  * @package Piwik_MobileMessaging_ReportRenderer
  */
 use Piwik\Common;
+use Piwik\View;
+use Piwik\ReportRenderer;
 use Piwik\Site;
 
 /**
  *
  * @package Piwik_MobileMessaging_ReportRenderer
  */
-class Piwik_MobileMessaging_ReportRenderer_Sms extends Piwik_ReportRenderer
+class Piwik_MobileMessaging_ReportRenderer_Sms extends ReportRenderer
 {
     const FLOAT_REGEXP = '/[-+]?[0-9]*[\.,]?[0-9]+/';
     const SMS_CONTENT_TYPE = 'text/plain';
@@ -30,17 +32,17 @@ class Piwik_MobileMessaging_ReportRenderer_Sms extends Piwik_ReportRenderer
 
     public function sendToDisk($filename)
     {
-        return Piwik_ReportRenderer::writeFile($filename, self::SMS_FILE_EXTENSION, $this->rendering);
+        return ReportRenderer::writeFile($filename, self::SMS_FILE_EXTENSION, $this->rendering);
     }
 
     public function sendToBrowserDownload($filename)
     {
-        Piwik_ReportRenderer::sendToBrowser($filename, self::SMS_FILE_EXTENSION, self::SMS_CONTENT_TYPE, $this->rendering);
+        ReportRenderer::sendToBrowser($filename, self::SMS_FILE_EXTENSION, self::SMS_CONTENT_TYPE, $this->rendering);
     }
 
     public function sendToBrowserInline($filename)
     {
-        Piwik_ReportRenderer::inlineToBrowser(self::SMS_CONTENT_TYPE, $this->rendering);
+        ReportRenderer::inlineToBrowser(self::SMS_CONTENT_TYPE, $this->rendering);
     }
 
     public function getRenderedReport()
@@ -114,7 +116,7 @@ class Piwik_MobileMessaging_ReportRenderer_Sms extends Piwik_ReportRenderer
             $siteHasECommerce[$idSite] = Site::isEcommerceEnabledFor($idSite);
         }
 
-        $view = new Piwik_View('@MobileMessaging/SMSReport');
+        $view = new View('@MobileMessaging/SMSReport');
         $view->assign("isGoalPluginEnabled", $isGoalPluginEnabled);
         $view->assign("reportRows", $dataRows);
         $view->assign("reportRowsMetadata", $reportRowsMetadata);
diff --git a/plugins/MobileMessaging/SMSProvider/Clockwork.php b/plugins/MobileMessaging/SMSProvider/Clockwork.php
index faf5effbc7..29a153c6da 100644
--- a/plugins/MobileMessaging/SMSProvider/Clockwork.php
+++ b/plugins/MobileMessaging/SMSProvider/Clockwork.php
@@ -9,6 +9,8 @@
  * @package Piwik_MobileMessaging_SMSProvider
  */
 
+use Piwik\Http;
+
 require_once PIWIK_INCLUDE_PATH . "/plugins/MobileMessaging/APIException.php";
 /**
  *
@@ -70,8 +72,8 @@ class Piwik_MobileMessaging_SMSProvider_Clockwork extends Piwik_MobileMessaging_
         $timeout = self::SOCKET_TIMEOUT;
 
         try {
-            $result = Piwik_Http::sendHttpRequestBy(
-                Piwik_Http::getTransportMethod(),
+            $result = Http::sendHttpRequestBy(
+                Http::getTransportMethod(),
                 $url,
                 $timeout,
                 $userAgent = null,
diff --git a/plugins/MultiSites/API.php b/plugins/MultiSites/API.php
index 2906edc981..6e4feeba76 100755
--- a/plugins/MultiSites/API.php
+++ b/plugins/MultiSites/API.php
@@ -8,12 +8,14 @@
  * @category Piwik_Plugins
  * @package Piwik_MultiSites
  */
+use Piwik\API\Request;
 use Piwik\Archive;
 use Piwik\DataTable\Filter\CalculateEvolutionFilter;
 use Piwik\Period\Range;
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\DataTable;
+use Piwik\TaskScheduler;
 use Piwik\Site;
 
 /**
@@ -132,7 +134,7 @@ class Piwik_MultiSites_API
             return $idSites;
         }
         $idSites = array();
-        $sites = Piwik_API_Request::processRequest('SitesManager.getPatternMatchSites',
+        $sites = Request::processRequest('SitesManager.getPatternMatchSites',
             array('pattern'   => $pattern,
                   // added because caller could overwrite these
                   'serialize' => 0,
@@ -180,7 +182,7 @@ class Piwik_MultiSites_API
                 // Hack: when this API function is called as a Scheduled Task, Super User status is enforced.
                 // This means this function would return ALL websites in all cases.
                 // Instead, we make sure that only the right set of data is returned
-                && !Piwik_TaskScheduler::isTaskBeingExecuted()
+                && !TaskScheduler::isTaskBeingExecuted()
             ) {
                 Site::setSites(
                     Piwik_SitesManager_API::getInstance()->getAllSites()
@@ -298,7 +300,7 @@ class Piwik_MultiSites_API
 
         // filter rows without visits
         // note: if only one website is queried and there are no visits, we can not remove the row otherwise
-        // Piwik_API_ResponseBuilder throws 'Call to a member function getColumns() on a non-object'
+        // ResponseBuilder throws 'Call to a member function getColumns() on a non-object'
         if ($multipleWebsitesRequested
         // We don't delete the 0 visits row, if "Enhanced" mode is on.
             && !$enhanced) {
diff --git a/plugins/MultiSites/Controller.php b/plugins/MultiSites/Controller.php
index 4986ba1abc..fd7ee849c8 100644
--- a/plugins/MultiSites/Controller.php
+++ b/plugins/MultiSites/Controller.php
@@ -13,13 +13,15 @@ use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Config;
 use Piwik\Date;
+use Piwik\Controller;
+use Piwik\View;
 use Piwik\Site;
 
 /**
  *
  * @package Piwik_MultiSites
  */
-class Piwik_MultiSites_Controller extends Piwik_Controller
+class Piwik_MultiSites_Controller extends Controller
 {
     protected $orderBy = 'visits';
     protected $order = 'desc';
@@ -122,7 +124,7 @@ class Piwik_MultiSites_Controller extends Piwik_Controller
 
         $this->applyPrettyMoney($digestableData);
 
-        $view = new Piwik_View("@MultiSites/getSitesInfo");
+        $view = new View("@MultiSites/getSitesInfo");
         $view->isWidgetized = $isWidgetized;
         $view->sitesData = array_values($digestableData);
         $view->evolutionBy = $this->evolutionBy;
diff --git a/plugins/Overlay/Controller.php b/plugins/Overlay/Controller.php
index d3bd8ab3b0..b034173e43 100644
--- a/plugins/Overlay/Controller.php
+++ b/plugins/Overlay/Controller.php
@@ -1,8 +1,11 @@
 <?php
+use Piwik\API\Request;
 use Piwik\Metrics;
 use Piwik\Piwik;
 use Piwik\Config;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\View;
 
 /**
  * Piwik - Open source web analytics
@@ -14,7 +17,7 @@ use Piwik\Common;
  * @package Piwik_Overlay
  */
 
-class Piwik_Overlay_Controller extends Piwik_Controller
+class Piwik_Overlay_Controller extends Controller
 {
 
     /** The index of the plugin */
@@ -27,7 +30,7 @@ class Piwik_Overlay_Controller extends Piwik_Controller
             $template = '@Overlay/index_noframe';
         }
 
-        $view = new Piwik_View($template);
+        $view = new View($template);
 
         $this->setGeneralVariablesView($view);
 
@@ -57,7 +60,7 @@ class Piwik_Overlay_Controller extends Piwik_Controller
         $path = Piwik_Actions_ArchivingHelper::getActionExplodedNames($normalizedCurrentUrl, Piwik_Tracker_Action::TYPE_ACTION_URL);
         $path = array_map('urlencode', $path);
         $label = implode('>', $path);
-        $request = new Piwik_API_Request(
+        $request = new Request(
             'method=Actions.getPageUrls'
                 . '&idSite=' . urlencode($idSite)
                 . '&date=' . urlencode($date)
@@ -103,7 +106,7 @@ class Piwik_Overlay_Controller extends Piwik_Controller
         }
 
         // render template
-        $view = new Piwik_View('@Overlay/renderSidebar');
+        $view = new View('@Overlay/renderSidebar');
         $view->data = $data;
         $view->location = $page;
         $view->normalizedUrl = $normalizedCurrentUrl;
@@ -197,7 +200,7 @@ class Piwik_Overlay_Controller extends Piwik_Controller
         $message = Piwik_Translate('Overlay_RedirectUrlError', array($url, "\n"));
         $message = nl2br(htmlentities($message));
 
-        $view = new Piwik_View('@Overlay/showErrorWrongDomain');
+        $view = new View('@Overlay/showErrorWrongDomain');
         $view->message = $message;
 
         if (Piwik::isUserHasAdminAccess($idSite)) {
@@ -224,7 +227,7 @@ class Piwik_Overlay_Controller extends Piwik_Controller
      */
     public function notifyParentIframe()
     {
-        $view = new Piwik_View('@Overlay/notifyParentIframe');
+        $view = new View('@Overlay/notifyParentIframe');
         echo $view->render();
     }
 
diff --git a/plugins/PDFReports/API.php b/plugins/PDFReports/API.php
index 4826fe8c80..7c07598430 100644
--- a/plugins/PDFReports/API.php
+++ b/plugins/PDFReports/API.php
@@ -11,6 +11,8 @@
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Date;
+use Piwik\ReportRenderer;
+use Piwik\ReportRenderer\Html;
 use Piwik\Site;
 use Piwik\Translate;
 
@@ -251,7 +253,7 @@ class Piwik_PDFReports_API
         }
 
         // Joining with the site table to work around pre-1.3 where reports could still be linked to a deleted site
-        $reports = Piwik_FetchAll("SELECT *
+        $reports = Db::fetchAll("SELECT *
 								FROM " . Common::prefixTable('report') . "
 									JOIN " . Common::prefixTable('site') . "
 									USING (idsite)
@@ -434,17 +436,17 @@ class Piwik_PDFReports_API
                 $outputFilename = $reportRenderer->sendToDisk($outputFilename);
 
                 $additionalFiles = array();
-                if ($reportRenderer instanceof Piwik_ReportRenderer_Html) {
+                if ($reportRenderer instanceof Html) {
                     foreach ($processedReports as &$report) {
                         if ($report['displayGraph']) {
                             $additionalFile = array();
                             $additionalFile['filename'] = $report['metadata']['name'] . '.png';
                             $additionalFile['cid'] = $report['metadata']['uniqueId'];
                             $additionalFile['content'] =
-                                Piwik_ReportRenderer::getStaticGraph(
+                                ReportRenderer::getStaticGraph(
                                     $report['metadata'],
-                                    Piwik_ReportRenderer_Html::IMAGE_GRAPH_WIDTH,
-                                    Piwik_ReportRenderer_Html::IMAGE_GRAPH_HEIGHT,
+                                    Html::IMAGE_GRAPH_WIDTH,
+                                    Html::IMAGE_GRAPH_HEIGHT,
                                     $report['evolutionGraph'],
                                     $segment
                                 );
diff --git a/plugins/PDFReports/Controller.php b/plugins/PDFReports/Controller.php
index 4e7e8c1644..3eed377084 100644
--- a/plugins/PDFReports/Controller.php
+++ b/plugins/PDFReports/Controller.php
@@ -10,18 +10,20 @@
  */
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\View;
 
 /**
  *
  * @package Piwik_PDFReports
  */
-class Piwik_PDFReports_Controller extends Piwik_Controller
+class Piwik_PDFReports_Controller extends Controller
 {
     const DEFAULT_REPORT_TYPE = Piwik_PDFReports::EMAIL_TYPE;
 
     public function index()
     {
-        $view = new Piwik_View('@PDFReports/index');
+        $view = new View('@PDFReports/index');
         $this->setGeneralVariablesView($view);
 
         $view->countWebsites = count(Piwik_SitesManager_API::getInstance()->getSitesIdWithAtLeastViewAccess());
diff --git a/plugins/PDFReports/PDFReports.php b/plugins/PDFReports/PDFReports.php
index 69ddb3d498..f9eb619ea1 100644
--- a/plugins/PDFReports/PDFReports.php
+++ b/plugins/PDFReports/PDFReports.php
@@ -12,6 +12,11 @@ use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Config;
 use Piwik\Date;
+use Piwik\Mail;
+use Piwik\View;
+use Piwik\ScheduledTime;
+use Piwik\ScheduledTask;
+use Piwik\ReportRenderer;
 use Piwik\Plugin;
 use Piwik\Site;
 
@@ -30,7 +35,7 @@ class Piwik_PDFReports extends Plugin
     const DISPLAY_FORMAT_TABLES_ONLY = 4; // Display only tables for all reports
     const DEFAULT_DISPLAY_FORMAT = self::DISPLAY_FORMAT_GRAPHS_ONLY_FOR_KEY_METRICS;
 
-    const DEFAULT_REPORT_FORMAT = Piwik_ReportRenderer::HTML_FORMAT;
+    const DEFAULT_REPORT_FORMAT = ReportRenderer::HTML_FORMAT;
     const DEFAULT_PERIOD = 'week';
     const DEFAULT_HOUR = '0';
 
@@ -55,8 +60,8 @@ class Piwik_PDFReports extends Plugin
     );
 
     static private $managedReportFormats = array(
-        Piwik_ReportRenderer::HTML_FORMAT => 'plugins/Zeitgeist/images/html_icon.png',
-        Piwik_ReportRenderer::PDF_FORMAT  => 'plugins/UserSettings/images/plugins/pdf.gif'
+        ReportRenderer::HTML_FORMAT => 'plugins/Zeitgeist/images/html_icon.png',
+        ReportRenderer::PDF_FORMAT  => 'plugins/UserSettings/images/plugins/pdf.gif'
     );
 
     /**
@@ -233,9 +238,9 @@ class Piwik_PDFReports extends Plugin
             $reportFormat = $notificationInfo[Piwik_PDFReports_API::REPORT_KEY]['format'];
             $outputType = $notificationInfo[Piwik_PDFReports_API::OUTPUT_TYPE_INFO_KEY];
 
-            $reportRenderer = Piwik_ReportRenderer::factory($reportFormat);
+            $reportRenderer = ReportRenderer::factory($reportFormat);
 
-            if ($reportFormat == Piwik_ReportRenderer::HTML_FORMAT) {
+            if ($reportFormat == ReportRenderer::HTML_FORMAT) {
                 $reportRenderer->setRenderImageInline($outputType != Piwik_PDFReports_API::OUTPUT_SAVE_ON_DISK);
             }
         }
@@ -262,7 +267,7 @@ class Piwik_PDFReports extends Plugin
             $message = Piwik_Translate('PDFReports_EmailHello');
             $subject = Piwik_Translate('General_Report') . ' ' . $reportTitle . " - " . $prettyDate;
 
-            $mail = new Piwik_Mail();
+            $mail = new Mail();
             $mail->setSubject($subject);
             $fromEmailName = Config::getInstance()->branding['use_custom_logo']
                 ? Piwik_Translate('CoreHome_WebAnalyticsReports')
@@ -392,7 +397,7 @@ class Piwik_PDFReports extends Plugin
 
     static public function template_reportParametersPDFReports(&$out)
     {
-        $view = new Piwik_View('@PDFReports/reportParametersPDFReports');
+        $view = new View('@PDFReports/reportParametersPDFReports');
         $view->currentUserEmail = Piwik::getCurrentUserEmail();
         $view->displayFormats = self::getDisplayFormats();
         $view->reportType = self::EMAIL_TYPE;
@@ -414,7 +419,7 @@ class Piwik_PDFReports extends Plugin
     {
         $arbitraryDateInUTC = Date::factory('2011-01-01');
         foreach (Piwik_PDFReports_API::getInstance()->getReports() as $report) {
-            if (!$report['deleted'] && $report['period'] != Piwik_ScheduledTime::PERIOD_NEVER) {
+            if (!$report['deleted'] && $report['period'] != ScheduledTime::PERIOD_NEVER) {
                 $midnightInSiteTimezone =
                     date(
                         'H',
@@ -426,9 +431,9 @@ class Piwik_PDFReports extends Plugin
 
                 $hourInUTC = (24 - $midnightInSiteTimezone + $report['hour']) % 24;
 
-                $schedule = Piwik_ScheduledTime::getScheduledTimeForPeriod($report['period']);
+                $schedule = ScheduledTime::getScheduledTimeForPeriod($report['period']);
                 $schedule->setHour($hourInUTC);
-                $tasks[] = new Piwik_ScheduledTask (
+                $tasks[] = new ScheduledTask (
                     Piwik_PDFReports_API::getInstance(),
                     'sendReport',
                     $report['idreport'], $schedule
@@ -508,7 +513,7 @@ class Piwik_PDFReports extends Plugin
 
     public function deleteUserReport($userLogin)
     {
-        Piwik_Query('DELETE FROM ' . Common::prefixTable('report') . ' WHERE login = ?', $userLogin);
+        Db::query('DELETE FROM ' . Common::prefixTable('report') . ' WHERE login = ?', $userLogin);
     }
 
     public function install()
@@ -533,7 +538,7 @@ class Piwik_PDFReports extends Plugin
 				) DEFAULT CHARSET=utf8';
         try {
             foreach ($queries as $query) {
-                Piwik_Exec($query);
+                Db::exec($query);
             }
         } catch (Exception $e) {
             if (!Zend_Registry::get('db')->isErrNo($e, '1050')) {
@@ -577,10 +582,10 @@ class Piwik_PDFReports extends Plugin
     static public function getPeriodToFrequency()
     {
         return array(
-            Piwik_ScheduledTime::PERIOD_NEVER => Piwik_Translate('General_Never'),
-            Piwik_ScheduledTime::PERIOD_DAY   => Piwik_Translate('General_Daily'),
-            Piwik_ScheduledTime::PERIOD_WEEK  => Piwik_Translate('General_Weekly'),
-            Piwik_ScheduledTime::PERIOD_MONTH => Piwik_Translate('General_Monthly'),
+            ScheduledTime::PERIOD_NEVER => Piwik_Translate('General_Never'),
+            ScheduledTime::PERIOD_DAY   => Piwik_Translate('General_Daily'),
+            ScheduledTime::PERIOD_WEEK  => Piwik_Translate('General_Weekly'),
+            ScheduledTime::PERIOD_MONTH => Piwik_Translate('General_Monthly'),
         );
     }
 
@@ -591,11 +596,11 @@ class Piwik_PDFReports extends Plugin
     static public function getPeriodToFrequencyAsAdjective()
     {
         return array(
-            Piwik_ScheduledTime::PERIOD_DAY   => Piwik_Translate('General_DailyReport'),
-            Piwik_ScheduledTime::PERIOD_WEEK  => Piwik_Translate('General_WeeklyReport'),
-            Piwik_ScheduledTime::PERIOD_MONTH => Piwik_Translate('General_MonthlyReport'),
-            Piwik_ScheduledTime::PERIOD_YEAR => Piwik_Translate('General_YearlyReport'),
-            Piwik_ScheduledTime::PERIOD_RANGE => Piwik_Translate('General_RangeReports'),
+            ScheduledTime::PERIOD_DAY   => Piwik_Translate('General_DailyReport'),
+            ScheduledTime::PERIOD_WEEK  => Piwik_Translate('General_WeeklyReport'),
+            ScheduledTime::PERIOD_MONTH => Piwik_Translate('General_MonthlyReport'),
+            ScheduledTime::PERIOD_YEAR => Piwik_Translate('General_YearlyReport'),
+            ScheduledTime::PERIOD_RANGE => Piwik_Translate('General_RangeReports'),
         );
     }
 }
diff --git a/plugins/PleineLune/PleineLune.php b/plugins/PleineLune/PleineLune.php
index 12b581bdc1..b19ed3e288 100644
--- a/plugins/PleineLune/PleineLune.php
+++ b/plugins/PleineLune/PleineLune.php
@@ -8,6 +8,7 @@
  * @category Piwik_Plugins
  * @package Piwik_PleineLune
  */
+use Piwik\AssetManager;
 use Piwik\Plugin;
 
 /**
@@ -19,7 +20,7 @@ class Piwik_PleineLune extends Plugin
     public function getListHooksRegistered()
     {
         return array(
-            Piwik_AssetManager::CSS_IMPORT_EVENT => 'getCssFiles',
+            AssetManager::CSS_IMPORT_EVENT => 'getCssFiles',
         );
     }
 
diff --git a/plugins/PrivacyManager/Controller.php b/plugins/PrivacyManager/Controller.php
index a3af0246be..c11fb5d7f0 100644
--- a/plugins/PrivacyManager/Controller.php
+++ b/plugins/PrivacyManager/Controller.php
@@ -9,15 +9,18 @@
  * @package Piwik_PrivacyManager
  */
 use Piwik\Config;
+use Piwik\Controller\Admin;
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Date;
+use Piwik\View;
+use Piwik\TaskScheduler;
 
 /**
  *
  * @package Piwik_PrivacyManager
  */
-class Piwik_PrivacyManager_Controller extends Piwik_Controller_Admin
+class Piwik_PrivacyManager_Controller extends Admin
 {
 
     const ANONYMIZE_IP_PLUGIN_NAME = "AnonymizeIP";
@@ -90,7 +93,7 @@ class Piwik_PrivacyManager_Controller extends Piwik_Controller_Admin
     public function getDatabaseSize()
     {
         Piwik::checkUserIsSuperUser();
-        $view = new Piwik_View('@PrivacyManager/getDatabaseSize');
+        $view = new View('@PrivacyManager/getDatabaseSize');
 
         $forceEstimate = Common::getRequestVar('forceEstimate', 0);
         $view->dbStats = $this->getDeleteDBSizeEstimate($getSettingsFromQuery = true, $forceEstimate);
@@ -112,7 +115,7 @@ class Piwik_PrivacyManager_Controller extends Piwik_Controller_Admin
     public function privacySettings()
     {
         Piwik::checkUserHasSomeAdminAccess();
-        $view = new Piwik_View('@PrivacyManager/privacySettings');
+        $view = new View('@PrivacyManager/privacySettings');
 
         if (Piwik::isUserIsSuperUser()) {
             $view->deleteData = $this->getDeleteDataInfo();
@@ -229,7 +232,7 @@ class Piwik_PrivacyManager_Controller extends Piwik_Controller_Admin
     {
         Piwik::checkUserIsSuperUser();
         $deleteDataInfos = array();
-        $taskScheduler = new Piwik_TaskScheduler();
+        $taskScheduler = new TaskScheduler();
         $deleteDataInfos["config"] = Piwik_PrivacyManager::getPurgeDataSettings();
         $deleteDataInfos["deleteTables"] =
             "<br/>" . implode(", ", Piwik_PrivacyManager_LogDataPurger::getDeleteTableLogTables());
diff --git a/plugins/PrivacyManager/LogDataPurger.php b/plugins/PrivacyManager/LogDataPurger.php
index 6d7a06b951..d4fa491b43 100755
--- a/plugins/PrivacyManager/LogDataPurger.php
+++ b/plugins/PrivacyManager/LogDataPurger.php
@@ -11,6 +11,7 @@
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Date;
+use Piwik\Db;
 
 /**
  * Purges the log_visit, log_conversion and related tables of old visit data.
@@ -73,7 +74,7 @@ class Piwik_PrivacyManager_LogDataPurger
         foreach ($logTables as $logTable) {
             // deleting from log_action must be handled differently, so we do it later
             if ($logTable != Common::prefixTable('log_action')) {
-                Piwik_DeleteAllRows($logTable, $where, $this->maxRowsToDeletePerQuery, array($maxIdVisit));
+                Db::deleteAllRows($logTable, $where, $this->maxRowsToDeletePerQuery, array($maxIdVisit));
             }
         }
 
@@ -86,7 +87,7 @@ class Piwik_PrivacyManager_LogDataPurger
         }
 
         // optimize table overhead after deletion
-        Piwik_OptimizeTables($logTables);
+        Db::optimizeTables($logTables);
     }
 
     /**
@@ -138,7 +139,7 @@ class Piwik_PrivacyManager_LogDataPurger
         // delete before unlocking tables so there's no chance a new log row that references an
         // unused action will be inserted.
         $this->deleteUnusedActions();
-        $this->unlockLogTables();
+        Db::unlockAllTables();
     }
 
     /**
@@ -150,7 +151,7 @@ class Piwik_PrivacyManager_LogDataPurger
         $logVisit = Common::prefixTable("log_visit");
 
         // get max idvisit
-        $maxIdVisit = Piwik_FetchOne("SELECT MAX(idvisit) FROM $logVisit");
+        $maxIdVisit = Db::fetchOne("SELECT MAX(idvisit) FROM $logVisit");
         if (empty($maxIdVisit)) {
             return false;
         }
@@ -165,13 +166,13 @@ class Piwik_PrivacyManager_LogDataPurger
 		      ORDER BY idvisit DESC
 		         LIMIT 1";
 
-        return Piwik_SegmentedFetchFirst($sql, $maxIdVisit, 0, -self::$selectSegmentSize);
+        return Db::segmentedFetchFirst($sql, $maxIdVisit, 0, -self::$selectSegmentSize);
     }
 
     private function getLogTableDeleteCount($table, $maxIdVisit)
     {
         $sql = "SELECT COUNT(*) FROM $table WHERE idvisit <= ?";
-        return (int)Piwik_FetchOne($sql, array($maxIdVisit));
+        return (int)Db::fetchOne($sql, array($maxIdVisit));
     }
 
     private function createTempTable()
@@ -180,7 +181,7 @@ class Piwik_PrivacyManager_LogDataPurger
 					idaction INT(11),
 					PRIMARY KEY (idaction)
 				)";
-        Piwik_Query($sql);
+        Db::query($sql);
     }
 
     private function getMaxIdsInLogTables()
@@ -191,7 +192,7 @@ class Piwik_PrivacyManager_LogDataPurger
         $result = array();
         foreach ($tables as $table) {
             $idCol = $idColumns[$table];
-            $result[$table] = Piwik_FetchOne("SELECT MAX($idCol) FROM " . Common::prefixTable($table));
+            $result[$table] = Db::fetchOne("SELECT MAX($idCol) FROM " . Common::prefixTable($table));
         }
 
         return $result;
@@ -214,10 +215,10 @@ class Piwik_PrivacyManager_LogDataPurger
                     $finish = $maxIds[$table];
                 } else {
                     $start = $maxIds[$table];
-                    $finish = Piwik_FetchOne("SELECT MAX($idCol) FROM " . Common::prefixTable($table));
+                    $finish = Db::fetchOne("SELECT MAX($idCol) FROM " . Common::prefixTable($table));
                 }
 
-                Piwik_SegmentedQuery($sql, $start, $finish, self::$selectSegmentSize);
+                Db::segmentedQuery($sql, $start, $finish, self::$selectSegmentSize);
             }
         }
 
@@ -231,7 +232,7 @@ class Piwik_PrivacyManager_LogDataPurger
 
     private function lockLogTables()
     {
-        Piwik_LockTables(
+        Db::lockTables(
             $readLocks = Common::prefixTables('log_conversion',
                 'log_link_visit_action',
                 'log_visit',
@@ -240,11 +241,6 @@ class Piwik_PrivacyManager_LogDataPurger
         );
     }
 
-    private function unlockLogTables()
-    {
-        Piwik_UnlockAllTables();
-    }
-
     private function deleteUnusedActions()
     {
         list($logActionTable, $tempTableName) = Common::prefixTables("log_action", self::TEMP_TABLE_NAME);
@@ -254,7 +250,7 @@ class Piwik_PrivacyManager_LogDataPurger
 				   LEFT JOIN $tempTableName tmp ON tmp.idaction = $logActionTable.idaction
 					   WHERE tmp.idaction IS NULL";
 
-        Piwik_Query($deleteSql);
+        Db::query($deleteSql);
     }
 
     private function getIdActionColumns()
diff --git a/plugins/PrivacyManager/PrivacyManager.php b/plugins/PrivacyManager/PrivacyManager.php
index 710232001b..4d01b4850a 100644
--- a/plugins/PrivacyManager/PrivacyManager.php
+++ b/plugins/PrivacyManager/PrivacyManager.php
@@ -13,6 +13,7 @@ use Piwik\Metrics;
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Date;
+use Piwik\ScheduledTask;
 use Piwik\Plugin;
 
 /**
@@ -70,13 +71,13 @@ class Piwik_PrivacyManager extends Plugin
         // both tasks are low priority so they will execute after most others, but not lowest, so
         // they will execute before the optimize tables task
 
-        $purgeReportDataTask = new Piwik_ScheduledTask(
-            $this, 'deleteReportData', null, new Piwik_ScheduledTime_Daily(), Piwik_ScheduledTask::LOW_PRIORITY
+        $purgeReportDataTask = new ScheduledTask(
+            $this, 'deleteReportData', null, new Piwik_ScheduledTime_Daily(), ScheduledTask::LOW_PRIORITY
         );
         $tasks[] = $purgeReportDataTask;
 
-        $purgeLogDataTask = new Piwik_ScheduledTask(
-            $this, 'deleteLogData', null, new Piwik_ScheduledTime_Daily(), Piwik_ScheduledTask::LOW_PRIORITY
+        $purgeLogDataTask = new ScheduledTask(
+            $this, 'deleteLogData', null, new Piwik_ScheduledTime_Daily(), ScheduledTask::LOW_PRIORITY
         );
         $tasks[] = $purgeLogDataTask;
     }
@@ -390,7 +391,7 @@ class Piwik_PrivacyManager extends Plugin
 
     private static function getMaxGoalId()
     {
-        return Piwik_FetchOne("SELECT MAX(idgoal) FROM " . Common::prefixTable('goal'));
+        return Db::fetchOne("SELECT MAX(idgoal) FROM " . Common::prefixTable('goal'));
     }
 }
 
diff --git a/plugins/PrivacyManager/ReportsPurger.php b/plugins/PrivacyManager/ReportsPurger.php
index a8ed8c3bfa..af527b6142 100755
--- a/plugins/PrivacyManager/ReportsPurger.php
+++ b/plugins/PrivacyManager/ReportsPurger.php
@@ -11,6 +11,7 @@
 use Piwik\DataAccess\ArchiveTableCreator;
 use Piwik\Piwik;
 use Piwik\Date;
+use Piwik\Db;
 
 /**
  * Purges archived reports and metrics that are considered old.
@@ -107,18 +108,18 @@ class Piwik_PrivacyManager_ReportsPurger
         if (!empty($oldBlobTables)) {
             // if no reports should be kept, drop tables, otherwise drop individual reports
             if (empty($this->reportPeriodsToKeep) && !$this->keepSegmentReports) {
-                Piwik_DropTables($oldBlobTables);
+                Db::dropTables($oldBlobTables);
             } else {
                 foreach ($oldBlobTables as $table) {
                     $where = $this->getBlobTableWhereExpr($oldNumericTables, $table);
                     if (!empty($where)) {
                         $where = "WHERE $where";
                     }
-                    Piwik_DeleteAllRows($table, $where, $this->maxRowsToDeletePerQuery);
+                    Db::deleteAllRows($table, $where, $this->maxRowsToDeletePerQuery);
                 }
 
                 if ($optimize) {
-                    Piwik_OptimizeTables($oldBlobTables);
+                    Db::optimizeTables($oldBlobTables);
                 }
             }
         }
@@ -129,15 +130,15 @@ class Piwik_PrivacyManager_ReportsPurger
             if ($this->keepBasicMetrics == 1 && !empty($this->metricsToKeep)) {
                 $where = "WHERE name NOT IN ('" . implode("','", $this->metricsToKeep) . "') AND name NOT LIKE 'done%'";
                 foreach ($oldNumericTables as $table) {
-                    Piwik_DeleteAllRows($table, $where, $this->maxRowsToDeletePerQuery);
+                    Db::deleteAllRows($table, $where, $this->maxRowsToDeletePerQuery);
                 }
 
                 if ($optimize) {
-                    Piwik_OptimizeTables($oldNumericTables);
+                    Db::optimizeTables($oldNumericTables);
                 }
             } else // drop numeric tables
             {
-                Piwik_DropTables($oldNumericTables);
+                Db::dropTables($oldNumericTables);
             }
         }
     }
@@ -249,7 +250,7 @@ class Piwik_PrivacyManager_ReportsPurger
 
     private function getNumericTableDeleteCount($table)
     {
-        $maxIdArchive = Piwik_FetchOne("SELECT MAX(idarchive) FROM $table");
+        $maxIdArchive = Db::fetchOne("SELECT MAX(idarchive) FROM $table");
 
         $sql = "SELECT COUNT(*)
 				  FROM $table
@@ -258,13 +259,13 @@ class Piwik_PrivacyManager_ReportsPurger
 				   AND idarchive >= ?
 				   AND idarchive < ?";
 
-        $segments = Piwik_SegmentedFetchOne($sql, 0, $maxIdArchive, self::$selectSegmentSize);
+        $segments = Db::segmentedFetchOne($sql, 0, $maxIdArchive, self::$selectSegmentSize);
         return array_sum($segments);
     }
 
     private function getBlobTableDeleteCount($oldNumericTables, $table)
     {
-        $maxIdArchive = Piwik_FetchOne("SELECT MAX(idarchive) FROM $table");
+        $maxIdArchive = Db::fetchOne("SELECT MAX(idarchive) FROM $table");
 
         $sql = "SELECT COUNT(*)
 				  FROM $table
@@ -272,7 +273,7 @@ class Piwik_PrivacyManager_ReportsPurger
 				   AND idarchive >= ?
 				   AND idarchive < ?";
 
-        $segments = Piwik_SegmentedFetchOne($sql, 0, $maxIdArchive, self::$selectSegmentSize);
+        $segments = Db::segmentedFetchOne($sql, 0, $maxIdArchive, self::$selectSegmentSize);
         return array_sum($segments);
     }
 
@@ -312,7 +313,7 @@ class Piwik_PrivacyManager_ReportsPurger
         foreach ($numericTables as $table) {
             $tableDate = ArchiveTableCreator::getDateFromTableName($table);
 
-            $maxIdArchive = Piwik_FetchOne("SELECT MAX(idarchive) FROM $table");
+            $maxIdArchive = Db::fetchOne("SELECT MAX(idarchive) FROM $table");
 
             $sql = "SELECT idarchive
 					  FROM $table
@@ -322,7 +323,7 @@ class Piwik_PrivacyManager_ReportsPurger
 					   AND idarchive < ?";
 
             $this->segmentArchiveIds[$tableDate] = array();
-            foreach (Piwik_SegmentedFetchAll($sql, 0, $maxIdArchive, self::$selectSegmentSize) as $row) {
+            foreach (Db::segmentedFetchAll($sql, 0, $maxIdArchive, self::$selectSegmentSize) as $row) {
                 $this->segmentArchiveIds[$tableDate][] = $row['idarchive'];
             }
         }
diff --git a/plugins/Provider/Controller.php b/plugins/Provider/Controller.php
index f59b8d1b29..078e10fb52 100644
--- a/plugins/Provider/Controller.php
+++ b/plugins/Provider/Controller.php
@@ -8,12 +8,14 @@
  * @category Piwik_Plugins
  * @package Piwik_Provider
  */
+use Piwik\Controller;
+use Piwik\ViewDataTable;
 
 /**
  *
  * @package Piwik_Provider
  */
-class Piwik_Provider_Controller extends Piwik_Controller
+class Piwik_Provider_Controller extends Controller
 {
     /**
      * Provider
@@ -22,7 +24,7 @@ class Piwik_Provider_Controller extends Piwik_Controller
      */
     function getProvider($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__, "Provider.getProvider");
 
         $this->setPeriodVariablesView($view);
diff --git a/plugins/Provider/Provider.php b/plugins/Provider/Provider.php
index fe448e7395..834c85034e 100644
--- a/plugins/Provider/Provider.php
+++ b/plugins/Provider/Provider.php
@@ -9,6 +9,8 @@
  * @package Piwik_Provider
  */
 use Piwik\Common;
+use Piwik\FrontController;
+use Piwik\IP;
 use Piwik\Plugin;
 use Piwik\ArchiveProcessor;
 
@@ -67,7 +69,7 @@ class Piwik_Provider extends Plugin
 
         // if the column already exist do not throw error. Could be installed twice...
         try {
-            Piwik_Exec($query);
+            Db::exec($query);
         } catch (Exception $e) {
             if (!Zend_Registry::get('db')->isErrNo($e, '1060')) {
                 throw $e;
@@ -80,12 +82,12 @@ class Piwik_Provider extends Plugin
     {
         // add column hostname / hostname ext in the visit table
         $query = "ALTER TABLE `" . Common::prefixTable('log_visit') . "` DROP `location_provider`";
-        Piwik_Exec($query);
+        Db::exec($query);
     }
 
     function addWidget()
     {
-        Piwik_AddWidget('General_Visitors', 'Provider_WidgetProviders', 'Provider', 'getProvider');
+        WidgetsList::add('General_Visitors', 'Provider_WidgetProviders', 'Provider', 'getProvider');
     }
 
     function addMenu()
@@ -109,7 +111,7 @@ class Piwik_Provider extends Plugin
             return;
         }
 
-        $ip = Piwik_IP::N2P($visitorInfo['location_ip']);
+        $ip = IP::N2P($visitorInfo['location_ip']);
 
         // In case the IP was anonymized, we should not continue since the DNS reverse lookup will fail and this will slow down tracking
         if (substr($ip, -2, 2) == '.0') {
@@ -180,14 +182,14 @@ class Piwik_Provider extends Plugin
      */
     private function getHost($ip)
     {
-        return trim(strtolower(@Piwik_IP::getHostByAddr($ip)));
+        return trim(strtolower(@IP::getHostByAddr($ip)));
     }
 
     static public function footerUserCountry(&$out)
     {
         $out = '<div>
 			<h2>' . Piwik_Translate('Provider_WidgetProviders') . '</h2>';
-        $out .= Piwik_FrontController::getInstance()->fetchDispatch('Provider', 'getProvider');
+        $out .= FrontController::getInstance()->fetchDispatch('Provider', 'getProvider');
         $out .= '</div>';
     }
 
diff --git a/plugins/Proxy/Controller.php b/plugins/Proxy/Controller.php
index 9f49505e97..6633a70f5d 100644
--- a/plugins/Proxy/Controller.php
+++ b/plugins/Proxy/Controller.php
@@ -10,13 +10,16 @@
  */
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\AssetManager;
+use Piwik\Controller;
+use Piwik\Url;
 
 /**
  * Controller for proxy services
  *
  * @package Piwik_Proxy
  */
-class Piwik_Proxy_Controller extends Piwik_Controller
+class Piwik_Proxy_Controller extends Controller
 {
     const TRANSPARENT_PNG_PIXEL = 'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAA1BMVEUAAACnej3aAAAAAXRSTlMAQObYZgAAAApJREFUCNdjYAAAAAIAAeIhvDMAAAAASUVORK5CYII=';
 
@@ -28,7 +31,7 @@ class Piwik_Proxy_Controller extends Piwik_Controller
      */
     public function getCss()
     {
-        $cssMergedFile = Piwik_AssetManager::getMergedCssFileLocation();
+        $cssMergedFile = AssetManager::getMergedCssFileLocation();
         Piwik::serveStaticFile($cssMergedFile, "text/css");
     }
 
@@ -40,7 +43,7 @@ class Piwik_Proxy_Controller extends Piwik_Controller
      */
     public function getJs()
     {
-        $jsMergedFile = Piwik_AssetManager::getMergedJsFileLocation();
+        $jsMergedFile = AssetManager::getMergedJsFileLocation();
         Piwik::serveStaticFile($jsMergedFile, "application/javascript; charset=UTF-8");
     }
 
@@ -55,8 +58,8 @@ class Piwik_Proxy_Controller extends Piwik_Controller
         $url = Common::getRequestVar('url', '', 'string', $_GET);
 
         // validate referrer
-        $referrer = Piwik_Url::getReferer();
-        if (empty($referrer) || !Piwik_Url::isLocalUrl($referrer)) {
+        $referrer = Url::getReferer();
+        if (empty($referrer) || !Url::isLocalUrl($referrer)) {
             die('Invalid Referer detected - This means that your web browser is not sending the "Referer URL" which is
 				required to proceed with the redirect. Verify your browser settings and add-ons, to check why your browser
 				 is not sending this referer.
diff --git a/plugins/Proxy/Proxy.php b/plugins/Proxy/Proxy.php
index fc404bfd2e..47d085a70c 100644
--- a/plugins/Proxy/Proxy.php
+++ b/plugins/Proxy/Proxy.php
@@ -8,6 +8,7 @@
  * @category Piwik_Plugins
  * @package Piwik_Proxy
  */
+use Piwik\Version;
 use Piwik\Plugin;
 
 /**
@@ -30,7 +31,7 @@ class Piwik_Proxy extends Plugin
             'description'          => 'Proxy services',
             'author'               => 'Piwik',
             'author_homepage'      => 'http://piwik.org/',
-            'version'              => Piwik_Version::VERSION,
+            'version'              => Version::VERSION,
             'translationAvailable' => false,
         );
     }
diff --git a/plugins/Referers/API.php b/plugins/Referers/API.php
index a8dba84e0d..495a73f53f 100644
--- a/plugins/Referers/API.php
+++ b/plugins/Referers/API.php
@@ -8,6 +8,7 @@
  * @category Piwik_Plugins
  * @package Piwik_Referers
  */
+use Piwik\API\ResponseBuilder;
 use Piwik\Archive;
 use Piwik\DataTable\Row;
 use Piwik\Metrics;
@@ -211,7 +212,7 @@ class Piwik_Referers_API
         $request['serialize'] = 0;
 
         // Apply generic filters
-        $response = new Piwik_API_ResponseBuilder($format = 'original', $request);
+        $response = new ResponseBuilder($format = 'original', $request);
         $table = $response->getResponse($table);
 
         // If period=lastX we only keep the first resultset as we want to return a plain list
diff --git a/plugins/Referers/Archiver.php b/plugins/Referers/Archiver.php
index dd7a795e9e..4da6a19d07 100644
--- a/plugins/Referers/Archiver.php
+++ b/plugins/Referers/Archiver.php
@@ -2,6 +2,7 @@
 use Piwik\Common;
 use Piwik\Config;
 use Piwik\Metrics;
+use Piwik\DataArray;
 use Piwik\PluginsArchiver;
 
 /**
@@ -29,7 +30,7 @@ class Piwik_Referers_Archiver extends PluginsArchiver
     protected $columnToSortByBeforeTruncation;
     protected $maximumRowsInDataTableLevelZero;
     protected $maximumRowsInSubDataTable;
-    /* @var array[Piwik_DataArray] $arrays */
+    /* @var array[DataArray] $arrays */
     protected $arrays = array();
     protected $distinctUrls = array();
 
@@ -44,7 +45,7 @@ class Piwik_Referers_Archiver extends PluginsArchiver
     public function archiveDay()
     {
         foreach ($this->getRecordNames() as $record) {
-            $this->arrays[$record] = new Piwik_DataArray();
+            $this->arrays[$record] = new DataArray();
         }
         $query = $this->getLogAggregator()->queryVisitsByDimension(array("referer_type", "referer_name", "referer_keyword", "referer_url"));
         $this->aggregateFromVisits($query);
@@ -127,7 +128,7 @@ class Piwik_Referers_Archiver extends PluginsArchiver
 
     /**
      * @param $name
-     * @return Piwik_DataArray
+     * @return DataArray
      */
     protected function getDataArray($name)
     {
@@ -149,7 +150,7 @@ class Piwik_Referers_Archiver extends PluginsArchiver
         }
 
         foreach ($this->arrays as $dataArray) {
-            /* @var Piwik_DataArray $dataArray */
+            /* @var DataArray $dataArray */
             $dataArray->enrichMetricsWithConversions();
         }
     }
diff --git a/plugins/Referers/Controller.php b/plugins/Referers/Controller.php
index 97d920e175..072fc1ec4a 100644
--- a/plugins/Referers/Controller.php
+++ b/plugins/Referers/Controller.php
@@ -8,20 +8,25 @@
  * @category Piwik_Plugins
  * @package Piwik_Referers
  */
+use Piwik\API\Request;
 use Piwik\Metrics;
 use Piwik\Period\Range;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\ViewDataTable;
+use Piwik\View;
+use Piwik\Url;
 
 /**
  *
  * @package Piwik_Referers
  */
-class Piwik_Referers_Controller extends Piwik_Controller
+class Piwik_Referers_Controller extends Controller
 {
     function index()
     {
-        $view = new Piwik_View('@Referers/index');
+        $view = new View('@Referers/index');
 
         $view->graphEvolutionReferers = $this->getEvolutionGraph(true, Common::REFERER_TYPE_DIRECT_ENTRY, array('nb_visits'));
         $view->nameGraphEvolutionReferers = 'ReferersgetEvolutionGraph';
@@ -124,7 +129,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function getSearchEnginesAndKeywords()
     {
-        $view = new Piwik_View('@Referers/getSearchEnginesAndKeywords');
+        $view = new View('@Referers/getSearchEnginesAndKeywords');
         $view->searchEngines = $this->getSearchEngines(true);
         $view->keywords = $this->getKeywords(true);
         echo $view->render();
@@ -132,7 +137,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function getRefererType($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory('tableAllColumns');
+        $view = ViewDataTable::factory('tableAllColumns');
         $view->init($this->pluginName,
             __FUNCTION__,
             'Referers.getRefererType',
@@ -179,7 +184,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
      */
     public function getAll($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__, 'Referers.getAll');
         $view->disableExcludeLowPopulation();
         $view->setColumnTranslation('label', Piwik_Translate('Referers_Referrer'));
@@ -235,7 +240,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function getKeywords($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__,
             'Referers.getKeywords',
             'getSearchEnginesFromKeywordId'
@@ -253,7 +258,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function getSearchEnginesFromKeywordId($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__,
             'Referers.getSearchEnginesFromKeywordId'
         );
@@ -267,7 +272,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function getSearchEngines($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__,
             'Referers.getSearchEngines',
             'getKeywordsFromSearchEngineId'
@@ -286,7 +291,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function getKeywordsFromSearchEngineId($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__,
             'Referers.getKeywordsFromSearchEngineId'
         );
@@ -299,7 +304,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function indexWebsites($fetch = false)
     {
-        $view = new Piwik_View('@Referers/indexWebsites');
+        $view = new View('@Referers/indexWebsites');
         $view->websites = $this->getWebsites(true);
         $view->socials = $this->getSocials(true);
         if ($fetch) {
@@ -311,7 +316,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function getWebsites($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__,
             'Referers.getWebsites',
             'getUrlsFromWebsiteId'
@@ -329,7 +334,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function getSocials($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory('graphPie');
+        $view = ViewDataTable::factory('graphPie');
         $view->init($this->pluginName, __FUNCTION__, 'Referers.getSocials', 'getUrlsForSocial');
         $view->disableExcludeLowPopulation();
         $view->setLimit(10);
@@ -348,7 +353,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function getUrlsForSocial($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__, 'Referers.getUrlsForSocial');
         $view->disableExcludeLowPopulation();
         $view->setLimit(10);
@@ -362,14 +367,14 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function indexCampaigns($fetch = false)
     {
-        return Piwik_View::singleReport(
+        return View::singleReport(
             Piwik_Translate('Referers_Campaigns'),
             $this->getCampaigns(true), $fetch);
     }
 
     function getCampaigns($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__,
             'Referers.getCampaigns',
             'getKeywordsFromCampaignId'
@@ -391,7 +396,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function getKeywordsFromCampaignId($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__,
             'Referers.getKeywordsFromCampaignId'
         );
@@ -406,7 +411,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
 
     function getUrlsFromWebsiteId($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__,
             'Referers.getUrlsFromWebsiteId'
         );
@@ -427,7 +432,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
         // we disable the queued filters because here we want to get the visits coming from search engines
         // if the filters were applied we would have to look up for a label looking like "Search Engines"
         // which is not good when we have translations
-        $dataTableReferersType = Piwik_API_Request::processRequest(
+        $dataTableReferersType = Request::processRequest(
             "Referers.getRefererType", array('disable_queued_filters' => '1', 'date' => $date));
 
         $nameToColumnId = array(
@@ -548,7 +553,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
             . '&method=Actions.getPageUrls'
             . '&filter_limit=50'
             . '&format=original';
-        $request = new Piwik_API_Request($topPageUrlRequest);
+        $request = new Request($topPageUrlRequest);
         $request = $request->process();
         $tables = $request->getArray();
 
@@ -566,7 +571,7 @@ class Piwik_Referers_Controller extends Piwik_Controller
         $url = $topPageUrl;
 
         // HTML
-        $api = Piwik_Url::getCurrentUrlWithoutFileName()
+        $api = Url::getCurrentUrlWithoutFileName()
             . '?module=API&method=Referers.getKeywordsForPageUrl'
             . '&format=php'
             . '&filter_limit=10'
@@ -711,9 +716,9 @@ function DisplayTopKeywords($url = "")
 
     /**
      * Utility method that calculates evolution values for a set of current & past values
-     * and sets properties on a Piwik_View w/ HTML that displays the evolution percents.
+     * and sets properties on a View w/ HTML that displays the evolution percents.
      *
-     * @param Piwik_View $view The view to set properties on.
+     * @param View $view The view to set properties on.
      * @param string $date The date of the current values.
      * @param array $currentValues Array mapping view property names w/ present values.
      * @param string $lastPeriodDate The date of the period in the past.
diff --git a/plugins/Referers/Referers.php b/plugins/Referers/Referers.php
index 449bc0ce41..cc8642df6e 100644
--- a/plugins/Referers/Referers.php
+++ b/plugins/Referers/Referers.php
@@ -208,15 +208,15 @@ class Piwik_Referers extends Plugin
      */
     function addWidgets()
     {
-        Piwik_AddWidget('Referers_Referers', 'Referers_WidgetKeywords', 'Referers', 'getKeywords');
-        Piwik_AddWidget('Referers_Referers', 'Referers_WidgetExternalWebsites', 'Referers', 'getWebsites');
-        Piwik_AddWidget('Referers_Referers', 'Referers_WidgetSocials', 'Referers', 'getSocials');
-        Piwik_AddWidget('Referers_Referers', 'Referers_WidgetSearchEngines', 'Referers', 'getSearchEngines');
-        Piwik_AddWidget('Referers_Referers', 'Referers_WidgetCampaigns', 'Referers', 'getCampaigns');
-        Piwik_AddWidget('Referers_Referers', 'Referers_WidgetOverview', 'Referers', 'getRefererType');
-        Piwik_AddWidget('Referers_Referers', 'Referers_WidgetGetAll', 'Referers', 'getAll');
+        WidgetsList::add('Referers_Referers', 'Referers_WidgetKeywords', 'Referers', 'getKeywords');
+        WidgetsList::add('Referers_Referers', 'Referers_WidgetExternalWebsites', 'Referers', 'getWebsites');
+        WidgetsList::add('Referers_Referers', 'Referers_WidgetSocials', 'Referers', 'getSocials');
+        WidgetsList::add('Referers_Referers', 'Referers_WidgetSearchEngines', 'Referers', 'getSearchEngines');
+        WidgetsList::add('Referers_Referers', 'Referers_WidgetCampaigns', 'Referers', 'getCampaigns');
+        WidgetsList::add('Referers_Referers', 'Referers_WidgetOverview', 'Referers', 'getRefererType');
+        WidgetsList::add('Referers_Referers', 'Referers_WidgetGetAll', 'Referers', 'getAll');
         if (Piwik::isSegmentationEnabled()) {
-            Piwik_AddWidget('SEO', 'Referers_WidgetTopKeywordsForPages', 'Referers', 'getKeywordsForPage');
+            WidgetsList::add('SEO', 'Referers_WidgetTopKeywordsForPages', 'Referers', 'getKeywordsForPage');
         }
     }
 
diff --git a/plugins/SEO/Controller.php b/plugins/SEO/Controller.php
index b509264871..207d92a179 100644
--- a/plugins/SEO/Controller.php
+++ b/plugins/SEO/Controller.php
@@ -10,12 +10,14 @@
  */
 use Piwik\Common;
 use Piwik\DataTable\Renderer;
+use Piwik\Controller;
+use Piwik\View;
 use Piwik\Site;
 
 /**
  * @package Piwik_SEO
  */
-class Piwik_SEO_Controller extends Piwik_Controller
+class Piwik_SEO_Controller extends Controller
 {
     function getRank()
     {
@@ -34,7 +36,7 @@ class Piwik_SEO_Controller extends Piwik_Controller
 
         $dataTable = Piwik_SEO_API::getInstance()->getRank($url);
 
-        $view = new Piwik_View('@SEO/getRank');
+        $view = new View('@SEO/getRank');
         $view->urlToRank = Piwik_SEO_RankChecker::extractDomainFromUrl($url);
 
         $renderer = Renderer::factory('php');
diff --git a/plugins/SEO/MajesticClient.php b/plugins/SEO/MajesticClient.php
index 250fa0025b..34f16a038e 100644
--- a/plugins/SEO/MajesticClient.php
+++ b/plugins/SEO/MajesticClient.php
@@ -9,6 +9,7 @@
  * @package Piwik_SEO
  */
 use Piwik\Common;
+use Piwik\Http;
 
 /**
  * Client for Majestic SEO's HTTP API.
@@ -57,7 +58,7 @@ class Piwik_SEO_MajesticClient
             'items' => '1',
             'item0' => $siteDomain
         ));
-        $apiResponse = Piwik_Http::sendHttpRequest($apiUrl, $timeout);
+        $apiResponse = Http::sendHttpRequest($apiUrl, $timeout);
 
         $result = array(
             'backlink_count'         => false,
diff --git a/plugins/SEO/RankChecker.php b/plugins/SEO/RankChecker.php
index aa4d44c87e..cdc858176c 100644
--- a/plugins/SEO/RankChecker.php
+++ b/plugins/SEO/RankChecker.php
@@ -9,6 +9,7 @@
  * @package Piwik_SEO
  */
 use Piwik\Piwik;
+use Piwik\Http;
 
 /**
  * The functions below are derived/adapted from GetRank.org's
@@ -56,7 +57,7 @@ class Piwik_SEO_RankChecker
     private function getPage($url)
     {
         try {
-            return str_replace('&nbsp;', ' ', Piwik_Http::sendHttpRequest($url, $timeout = 10, @$_SERVER['HTTP_USER_AGENT']));
+            return str_replace('&nbsp;', ' ', Http::sendHttpRequest($url, $timeout = 10, @$_SERVER['HTTP_USER_AGENT']));
         } catch (Exception $e) {
             return '';
         }
diff --git a/plugins/SEO/SEO.php b/plugins/SEO/SEO.php
index e41c93385c..9d5b68efe9 100644
--- a/plugins/SEO/SEO.php
+++ b/plugins/SEO/SEO.php
@@ -8,6 +8,7 @@
  * @category Piwik_Plugins
  * @package Piwik_SEO
  */
+use Piwik\Version;
 use Piwik\Plugin;
 
 /**
@@ -24,7 +25,7 @@ class Piwik_SEO extends Plugin
             'description'     => 'This Plugin extracts and displays SEO metrics: Alexa web ranking, Google Pagerank, number of Indexed pages and backlinks of the currently selected website.',
             'author'          => 'Piwik',
             'author_homepage' => 'http://piwik.org/',
-            'version'         => Piwik_Version::VERSION,
+            'version'         => Version::VERSION,
         );
     }
 
@@ -39,6 +40,6 @@ class Piwik_SEO extends Plugin
 
     function addWidgets()
     {
-        Piwik_AddWidget('SEO', 'SEO_SeoRankings', 'SEO', 'getRank');
+        WidgetsList::add('SEO', 'SEO_SeoRankings', 'SEO', 'getRank');
     }
 }
diff --git a/plugins/SecurityInfo/Controller.php b/plugins/SecurityInfo/Controller.php
index c9b307bba4..7195185fdd 100644
--- a/plugins/SecurityInfo/Controller.php
+++ b/plugins/SecurityInfo/Controller.php
@@ -8,12 +8,14 @@
  * @category Piwik_Plugins
  * @package Piwik_SecurityInfo
  */
+use Piwik\Controller\Admin;
 use Piwik\Piwik;
+use Piwik\View;
 
 /**
  * @package Piwik_SecurityInfo
  */
-class Piwik_SecurityInfo_Controller extends Piwik_Controller_Admin
+class Piwik_SecurityInfo_Controller extends Admin
 {
     function index()
     {
@@ -35,7 +37,7 @@ class Piwik_SecurityInfo_Controller extends Piwik_Controller_Admin
         unset($results['test_results']['Core']['post_max_size']);
         unset($results['test_results']['Core']['upload_max_filesize']);
 
-        $view = new Piwik_View('@SecurityInfo/index');
+        $view = new View('@SecurityInfo/index');
         $this->setBasicVariablesView($view);
         $view->results = $results;
         echo $view->render();
diff --git a/plugins/SecurityInfo/PhpSecInfo/Test/Application/php.php b/plugins/SecurityInfo/PhpSecInfo/Test/Application/php.php
index 3199cb3167..98b170f427 100644
--- a/plugins/SecurityInfo/PhpSecInfo/Test/Application/php.php
+++ b/plugins/SecurityInfo/PhpSecInfo/Test/Application/php.php
@@ -5,6 +5,8 @@
  * @package PhpSecInfo
  * @author Piwik
  */
+use Piwik\Http;
+use Piwik\UpdateCheck;
 
 /**
  * require the PhpSecInfo_Test_Application class
@@ -30,9 +32,9 @@ class PhpSecInfo_Test_Application_Php extends PhpSecInfo_Test_Application
         $this->current_value = PHP_VERSION;
 
         $url = 'http://php.net/releases/?serialize=1&version=5';
-        $timeout = Piwik_UpdateCheck::SOCKET_TIMEOUT;
+        $timeout = UpdateCheck::SOCKET_TIMEOUT;
         try {
-            $latestVersion = Piwik_Http::sendHttpRequest($url, $timeout);
+            $latestVersion = Http::sendHttpRequest($url, $timeout);
             $versionInfo = safe_unserialize($latestVersion);
             $this->recommended_value = $versionInfo['version'];
         } catch (Exception $e) {
diff --git a/plugins/SecurityInfo/PhpSecInfo/Test/Application/piwik.php b/plugins/SecurityInfo/PhpSecInfo/Test/Application/piwik.php
index 16e7fbf42f..e3aa84f16b 100644
--- a/plugins/SecurityInfo/PhpSecInfo/Test/Application/piwik.php
+++ b/plugins/SecurityInfo/PhpSecInfo/Test/Application/piwik.php
@@ -5,6 +5,8 @@
  * @package PhpSecInfo
  * @author Piwik
  */
+use Piwik\Version;
+use Piwik\UpdateCheck;
 
 /**
  * require the PhpSecInfo_Test_Application class
@@ -27,9 +29,9 @@ class PhpSecInfo_Test_Application_Piwik extends PhpSecInfo_Test_Application
 
     function _retrieveCurrentValue()
     {
-        $this->current_value = Piwik_Version::VERSION;
+        $this->current_value = Version::VERSION;
 
-        $this->recommended_value = Piwik_GetOption(Piwik_UpdateCheck::LATEST_VERSION);
+        $this->recommended_value = Piwik_GetOption(UpdateCheck::LATEST_VERSION);
     }
 
     function _execTest()
diff --git a/plugins/SecurityInfo/PhpSecInfo/Test/Test_Application.php b/plugins/SecurityInfo/PhpSecInfo/Test/Test_Application.php
index af97310aad..c87b9d2856 100644
--- a/plugins/SecurityInfo/PhpSecInfo/Test/Test_Application.php
+++ b/plugins/SecurityInfo/PhpSecInfo/Test/Test_Application.php
@@ -5,6 +5,7 @@
  * @package PhpSecInfo
  * @author Anthon Pang
  */
+use Piwik\Http;
 
 /**
  * require the main PhpSecInfo class
@@ -36,7 +37,7 @@ class PhpSecInfo_Test_Application extends PhpSecInfo_Test
      */
     function isTestable()
     {
-        return Piwik_Http::getTransportMethod() !== null;
+        return Http::getTransportMethod() !== null;
     }
 
     function getMoreInfoURL()
diff --git a/plugins/SegmentEditor/Controller.php b/plugins/SegmentEditor/Controller.php
index bafab7ac46..4083369ece 100644
--- a/plugins/SegmentEditor/Controller.php
+++ b/plugins/SegmentEditor/Controller.php
@@ -10,16 +10,18 @@
  */
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\View;
 
 /**
  * @package Piwik_SegmentEditor
  */
-class Piwik_SegmentEditor_Controller extends Piwik_Controller
+class Piwik_SegmentEditor_Controller extends Controller
 {
 
     public function getSelector()
     {
-        $view = new Piwik_View('@SegmentEditor/getSelector');
+        $view = new View('@SegmentEditor/getSelector');
         $idSite = Common::getRequestVar('idSite');
         $this->setGeneralVariablesView($view);
         $segments = Piwik_API_API::getInstance()->getSegmentsMetadata($idSite);
diff --git a/plugins/SegmentEditor/SegmentEditor.php b/plugins/SegmentEditor/SegmentEditor.php
index a4f54d01e7..0d539b078f 100644
--- a/plugins/SegmentEditor/SegmentEditor.php
+++ b/plugins/SegmentEditor/SegmentEditor.php
@@ -9,6 +9,7 @@
  * @package Piwik_SegmentEditor
  */
 use Piwik\Common;
+use Piwik\Version;
 use Piwik\Plugin;
 
 /**
@@ -25,7 +26,7 @@ class Piwik_SegmentEditor extends Plugin
             'description'     => 'Create and reuse custom visitor Segments with the Segment Editor.',
             'author'          => 'Piwik',
             'author_homepage' => 'http://piwik.org/',
-            'version'         => Piwik_Version::VERSION,
+            'version'         => Version::VERSION,
         );
     }
 
@@ -84,7 +85,7 @@ class Piwik_SegmentEditor extends Plugin
 				) DEFAULT CHARSET=utf8';
         try {
             foreach ($queries as $query) {
-                Piwik_Exec($query);
+                Db::exec($query);
             }
         } catch (Exception $e) {
             if (!Zend_Registry::get('db')->isErrNo($e, '1050')) {
diff --git a/plugins/SitesManager/API.php b/plugins/SitesManager/API.php
index edc66625e6..47b3e44f1d 100644
--- a/plugins/SitesManager/API.php
+++ b/plugins/SitesManager/API.php
@@ -12,6 +12,9 @@ use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Access;
 use Piwik\Date;
+use Piwik\IP;
+use Piwik\Url;
+use Piwik\TaskScheduler;
 use Piwik\Site;
 
 /**
@@ -69,7 +72,7 @@ class Piwik_SitesManager_API
         Piwik::checkUserHasViewAccess($idSite);
 
         if (empty($piwikUrl)) {
-            $piwikUrl = Piwik_Url::getCurrentUrlWithoutFileName();
+            $piwikUrl = Url::getCurrentUrlWithoutFileName();
         }
         $piwikUrl = Common::sanitizeInputValues($piwikUrl);
 
@@ -170,7 +173,7 @@ class Piwik_SitesManager_API
      */
     private function getSitesId()
     {
-        $result = Piwik_FetchAll("SELECT idsite FROM " . Common::prefixTable('site'));
+        $result = Db::fetchAll("SELECT idsite FROM " . Common::prefixTable('site'));
         $idSites = array();
         foreach ($result as $idSite) {
             $idSites[] = $idSite['idsite'];
@@ -225,7 +228,7 @@ class Piwik_SitesManager_API
         if (empty($timestamp)) $timestamp = time();
 
         $time = Date::factory((int)$timestamp)->getDatetime();
-        $result = Piwik_FetchAll("
+        $result = Db::fetchAll("
             SELECT
                 idsite
             FROM
@@ -321,7 +324,7 @@ class Piwik_SitesManager_API
             // but during scheduled task execution, we sometimes want to restrict sites to
             // a different login than the superuser.
             && (Piwik::isUserIsSuperUserOrTheUser($_restrictSitesToLogin)
-                || Piwik_TaskScheduler::isTaskBeingExecuted())
+                || TaskScheduler::isTaskBeingExecuted())
         ) {
             $accessRaw = Access::getInstance()->getRawSitesWithSomeViewAccess($_restrictSitesToLogin);
             $sitesId = array();
@@ -681,12 +684,12 @@ class Piwik_SitesManager_API
      */
     public function getIpsForRange($ipRange)
     {
-        $range = Piwik_IP::getIpsForRange($ipRange);
+        $range = IP::getIpsForRange($ipRange);
         if ($range === false) {
             return false;
         }
 
-        return array(Piwik_IP::N2P($range[0]), Piwik_IP::N2P($range[1]));
+        return array(IP::N2P($range[0]), IP::N2P($range[1]));
     }
 
     /**
@@ -1164,7 +1167,7 @@ class Piwik_SitesManager_API
     public function getUniqueSiteTimezones()
     {
         Piwik::checkUserIsSuperUser();
-        $results = Piwik_FetchAll("SELECT distinct timezone FROM " . Common::prefixTable('site'));
+        $results = Db::fetchAll("SELECT distinct timezone FROM " . Common::prefixTable('site'));
         $timezones = array();
         foreach ($results as $result) {
             $timezones[] = $result['timezone'];
@@ -1237,7 +1240,7 @@ class Piwik_SitesManager_API
      */
     private function isValidIp($ip)
     {
-        return Piwik_IP::getIpsForRange($ip) !== false;
+        return IP::getIpsForRange($ip) !== false;
     }
 
     /**
diff --git a/plugins/SitesManager/Controller.php b/plugins/SitesManager/Controller.php
index afbd9d21ed..3a8f339693 100644
--- a/plugins/SitesManager/Controller.php
+++ b/plugins/SitesManager/Controller.php
@@ -8,24 +8,29 @@
  * @category Piwik_Plugins
  * @package Piwik_SitesManager
  */
+use Piwik\API\ResponseBuilder;
+use Piwik\Controller\Admin;
 use Piwik\DataTable\Renderer\Json;
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Date;
+use Piwik\IP;
+use Piwik\View;
+use Piwik\Url;
 use Piwik\Site;
 
 /**
  *
  * @package Piwik_SitesManager
  */
-class Piwik_SitesManager_Controller extends Piwik_Controller_Admin
+class Piwik_SitesManager_Controller extends Admin
 {
     /**
      * Main view showing listing of websites and settings
      */
     public function index()
     {
-        $view = new Piwik_View('@SitesManager/index');
+        $view = new View('@SitesManager/index');
 
         if (Piwik::isUserIsSuperUser()) {
             $sites = Piwik_SitesManager_API::getInstance()->getAllSites();
@@ -70,7 +75,7 @@ class Piwik_SitesManager_Controller extends Piwik_Controller_Admin
 
         $view->globalKeepURLFragments = Piwik_SitesManager_API::getInstance()->getKeepURLFragmentsGlobal();
 
-        $view->currentIpAddress = Piwik_IP::getIpFromHeader();
+        $view->currentIpAddress = IP::getIpFromHeader();
 
         $view->showAddSite = (boolean)Common::getRequestVar('showaddsite', false);
 
@@ -83,7 +88,7 @@ class Piwik_SitesManager_Controller extends Piwik_Controller_Admin
      */
     public function setGlobalSettings()
     {
-        $response = new Piwik_API_ResponseBuilder(Common::getRequestVar('format'));
+        $response = new ResponseBuilder(Common::getRequestVar('format'));
 
         try {
             $this->checkTokenInUrl();
@@ -122,8 +127,8 @@ class Piwik_SitesManager_Controller extends Piwik_Controller_Admin
     {
         $idSite = Common::getRequestVar('idSite');
         Piwik::checkUserHasViewAccess($idSite);
-        $jsTag = Piwik::getJavascriptCode($idSite, Piwik_Url::getCurrentUrlWithoutFileName());
-        $view = new Piwik_View('@SitesManager/displayJavascriptCode');
+        $jsTag = Piwik::getJavascriptCode($idSite, Url::getCurrentUrlWithoutFileName());
+        $view = new View('@SitesManager/displayJavascriptCode');
         $this->setBasicVariablesView($view);
         $view->idSite = $idSite;
         $site = new Site($idSite);
@@ -149,7 +154,7 @@ class Piwik_SitesManager_Controller extends Piwik_Controller_Admin
      */
     function displayAlternativeTagsHelp()
     {
-        $view = new Piwik_View('@SitesManager/displayAlternativeTagsHelp');
+        $view = new View('@SitesManager/displayAlternativeTagsHelp');
         $view->idSite = Common::getRequestVar('idSite');
         $url = Common::getRequestVar('piwikUrl', '', 'string');
         if (empty($url)
diff --git a/plugins/Transitions/API.php b/plugins/Transitions/API.php
index ac04dac368..4b4e034750 100644
--- a/plugins/Transitions/API.php
+++ b/plugins/Transitions/API.php
@@ -19,6 +19,8 @@ use Piwik\Period\Day;
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\DataTable;
+use Piwik\DataArray;
+use Piwik\RankingQuery;
 use Piwik\Segment;
 use Piwik\SegmentExpression;
 use Piwik\Site;
@@ -286,7 +288,7 @@ class Piwik_Transitions_API
         $types[Piwik_Tracker_Action::TYPE_OUTLINK] = 'outlinks';
         $types[Piwik_Tracker_Action::TYPE_DOWNLOAD] = 'downloads';
 
-        $rankingQuery = new Piwik_RankingQuery($limitBeforeGrouping ? $limitBeforeGrouping : $this->limitBeforeGrouping);
+        $rankingQuery = new RankingQuery($limitBeforeGrouping ? $limitBeforeGrouping : $this->limitBeforeGrouping);
         $rankingQuery->addLabelColumn(array('name', 'url_prefix'));
         $rankingQuery->partitionResultIntoMultipleGroups('type', array_keys($types));
 
@@ -343,7 +345,7 @@ class Piwik_Transitions_API
      */
     public function queryExternalReferrers($idaction, $actionType, $logAggregator, $limitBeforeGrouping = false)
     {
-        $rankingQuery = new Piwik_RankingQuery($limitBeforeGrouping ? $limitBeforeGrouping : $this->limitBeforeGrouping);
+        $rankingQuery = new RankingQuery($limitBeforeGrouping ? $limitBeforeGrouping : $this->limitBeforeGrouping);
 
         // we generate a single column that contains the interesting data for each referrer.
         // the reason we cannot group by referer_* becomes clear when we look at search engine keywords.
@@ -401,7 +403,7 @@ class Piwik_Transitions_API
         }
 
         //FIXMEA refactor after integration tests written
-        $array = new Piwik_DataArray($referrerData, $referrerSubData);
+        $array = new DataArray($referrerData, $referrerSubData);
         return Day::getDataTableFromDataArray($array);
     }
 
@@ -416,7 +418,7 @@ class Piwik_Transitions_API
      */
     protected function queryInternalReferrers($idaction, $actionType, $logAggregator, $limitBeforeGrouping = false)
     {
-        $rankingQuery = new Piwik_RankingQuery($limitBeforeGrouping ? $limitBeforeGrouping : $this->limitBeforeGrouping);
+        $rankingQuery = new RankingQuery($limitBeforeGrouping ? $limitBeforeGrouping : $this->limitBeforeGrouping);
         $rankingQuery->addLabelColumn(array('name', 'url_prefix'));
         $rankingQuery->setColumnToMarkExcludedRows('is_self');
         $rankingQuery->partitionResultIntoMultipleGroups('action_partition', array(0, 1, 2));
@@ -588,7 +590,7 @@ class Piwik_Transitions_API
             }
         }
 
-        // if there's no data for referrers, Piwik_API_ResponseBuilder::handleMultiDimensionalArray
+        // if there's no data for referrers, ResponseBuilder::handleMultiDimensionalArray
         // does not detect the multi dimensional array and the data is rendered differently, which
         // causes an exception.
         if (count($report['referrers']) == 0) {
diff --git a/plugins/Transitions/Controller.php b/plugins/Transitions/Controller.php
index 01b72bb7ff..5178b1923f 100644
--- a/plugins/Transitions/Controller.php
+++ b/plugins/Transitions/Controller.php
@@ -8,11 +8,13 @@
  * @category Piwik_Plugins
  * @package Piwik_Transitions
  */
+use Piwik\Controller;
+use Piwik\View;
 
 /**
  * @package Piwik_Transitions
  */
-class Piwik_Transitions_Controller extends Piwik_Controller
+class Piwik_Transitions_Controller extends Controller
 {
 
     /**
@@ -74,7 +76,7 @@ class Piwik_Transitions_Controller extends Piwik_Controller
      */
     public function renderPopover()
     {
-        $view = new Piwik_View('@Transitions/renderPopover');
+        $view = new View('@Transitions/renderPopover');
         $view->translations = $this->getTranslations();
         echo $view->render();
     }
diff --git a/plugins/Transitions/javascripts/transitions.js b/plugins/Transitions/javascripts/transitions.js
index 14ccd28a19..6f0a633bec 100644
--- a/plugins/Transitions/javascripts/transitions.js
+++ b/plugins/Transitions/javascripts/transitions.js
@@ -47,7 +47,7 @@ DataTable_RowActions_Transitions.prototype.trigger = function (tr, e, subTableLa
 };
 
 DataTable_RowAction.prototype.performAction = function (label, tr, e) {
-    var separator = ' > '; // Piwik_API_DataTableManipulator_LabelFilter::SEPARATOR_RECURSIVE_LABEL
+    var separator = ' > '; // LabelFilter::SEPARATOR_RECURSIVE_LABEL
     var labelParts = label.split(separator);
     for (var i = 0; i < labelParts.length; i++) {
         labelParts[i] = $.trim(decodeURIComponent(labelParts[i]));
diff --git a/plugins/UserCountry/Archiver.php b/plugins/UserCountry/Archiver.php
index 129da79557..4544f2b764 100644
--- a/plugins/UserCountry/Archiver.php
+++ b/plugins/UserCountry/Archiver.php
@@ -12,6 +12,7 @@
 use Piwik\ArchiveProcessor\Day;
 use Piwik\Metrics;
 use Piwik\DataTable;
+use Piwik\DataArray;
 use Piwik\PluginsArchiver;
 
 class Piwik_UserCountry_Archiver extends PluginsArchiver
@@ -44,7 +45,7 @@ class Piwik_UserCountry_Archiver extends PluginsArchiver
     public function archiveDay()
     {
         foreach($this->dimensions as $dimension) {
-            $this->arrays[$dimension] = new Piwik_DataArray();
+            $this->arrays[$dimension] = new DataArray();
         }
         $this->aggregateFromVisits();
         $this->aggregateFromConversions();
@@ -64,7 +65,7 @@ class Piwik_UserCountry_Archiver extends PluginsArchiver
             $this->makeRegionCityLabelsUnique($row);
             $this->rememberCityLatLong($row);
 
-            /* @var $dataArray Piwik_DataArray */
+            /* @var $dataArray DataArray */
             foreach ($this->arrays as $dimension => $dataArray) {
                 $dataArray->sumMetricsVisits($row[$dimension], $row);
             }
@@ -113,13 +114,13 @@ class Piwik_UserCountry_Archiver extends PluginsArchiver
         while ($row = $query->fetch()) {
             $this->makeRegionCityLabelsUnique($row);
 
-            /* @var $dataArray Piwik_DataArray */
+            /* @var $dataArray DataArray */
             foreach ($this->arrays as $dimension => $dataArray) {
                 $dataArray->sumMetricsGoals($row[$dimension], $row);
             }
         }
 
-        /* @var $dataArray Piwik_DataArray */
+        /* @var $dataArray DataArray */
         foreach ($this->arrays as $dataArray) {
             $dataArray->enrichMetricsWithConversions();
         }
diff --git a/plugins/UserCountry/Controller.php b/plugins/UserCountry/Controller.php
index 9c547ee6dc..1fcd911832 100644
--- a/plugins/UserCountry/Controller.php
+++ b/plugins/UserCountry/Controller.php
@@ -8,19 +8,25 @@
  * @category Piwik_Plugins
  * @package Piwik_UserCountry
  */
+use Piwik\Controller\Admin;
 use Piwik\DataTable\Renderer\Json;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Http;
+use Piwik\IP;
+use Piwik\ViewDataTable;
+use Piwik\View;
+use Piwik\Url;
 
 /**
  *
  * @package Piwik_UserCountry
  */
-class Piwik_UserCountry_Controller extends Piwik_Controller_Admin
+class Piwik_UserCountry_Controller extends Admin
 {
     function index()
     {
-        $view = new Piwik_View('@UserCountry/index');
+        $view = new View('@UserCountry/index');
 
         $view->urlSparklineCountries = $this->getUrlSparkline('getLastDistinctCountriesGraph');
         $view->numberDistinctCountries = $this->getNumberOfDistinctCountries(true);
@@ -36,13 +42,13 @@ class Piwik_UserCountry_Controller extends Piwik_Controller_Admin
     function adminIndex()
     {
         Piwik::checkUserIsSuperUser();
-        $view = new Piwik_View('@UserCountry/adminIndex');
+        $view = new View('@UserCountry/adminIndex');
 
         $allProviderInfo = Piwik_UserCountry_LocationProvider::getAllProviderInfo(
             $newline = '<br/>', $includeExtra = true);
         $view->locationProviders = $allProviderInfo;
         $view->currentProviderId = Piwik_UserCountry_LocationProvider::getCurrentProviderId();
-        $view->thisIP = Piwik_IP::getIpFromHeader();
+        $view->thisIP = IP::getIpFromHeader();
         $geoIPDatabasesInstalled = Piwik_UserCountry_LocationProvider_GeoIp::isDatabaseInstalled();
         $view->geoIPDatabasesInstalled = $geoIPDatabasesInstalled;
 
@@ -72,7 +78,7 @@ class Piwik_UserCountry_Controller extends Piwik_Controller_Admin
 
         $this->setUpdaterManageVars($view);
         $this->setBasicVariablesView($view);
-        Piwik_Controller_Admin::setBasicVariablesAdminView($view);
+        Admin::setBasicVariablesAdminView($view);
 
         echo $view->render();
     }
@@ -102,7 +108,7 @@ class Piwik_UserCountry_Controller extends Piwik_Controller_Admin
             Json::sendHeaderJSON();
             $outputPath = Piwik_UserCountry_LocationProvider_GeoIp::getPathForGeoIpDatabase('GeoIPCity.dat') . '.gz';
             try {
-                $result = Piwik_Http::downloadChunk(
+                $result = Http::downloadChunk(
                     $url = Piwik_UserCountry_LocationProvider_GeoIp::GEO_LITE_URL,
                     $outputPath,
                     $continue = Common::getRequestVar('continue', true, 'int')
@@ -136,7 +142,7 @@ class Piwik_UserCountry_Controller extends Piwik_Controller_Admin
      */
     private function getGeoIpUpdaterManageScreen()
     {
-        $view = new Piwik_View('@UserCountry/getGeoIpUpdaterManageScreen');
+        $view = new View('@UserCountry/getGeoIpUpdaterManageScreen');
         $view->geoIPDatabasesInstalled = true;
         $this->setUpdaterManageVars($view);
         return $view->render();
@@ -145,7 +151,7 @@ class Piwik_UserCountry_Controller extends Piwik_Controller_Admin
     /**
      * Sets some variables needed by the _updaterManage.twig template.
      *
-     * @param Piwik_View $view
+     * @param View $view
      */
     private function setUpdaterManageVars($view)
     {
@@ -242,7 +248,7 @@ class Piwik_UserCountry_Controller extends Piwik_Controller_Admin
                 $outputPath = Piwik_UserCountry_LocationProvider_GeoIp::getPathForGeoIpDatabase($filename);
 
                 // download part of the file
-                $result = Piwik_Http::downloadChunk(
+                $result = Http::downloadChunk(
                     $url, $outputPath, Common::getRequestVar('continue', true, 'int'));
 
                 // if the file is done
@@ -304,7 +310,7 @@ class Piwik_UserCountry_Controller extends Piwik_Controller_Admin
             throw new Exception("Invalid provider ID: '$providerId'.");
         }
 
-        $location = $provider->getLocation(array('ip'                => Piwik_IP::getIpFromHeader(),
+        $location = $provider->getLocation(array('ip'                => IP::getIpFromHeader(),
                                                  'lang'              => Common::getBrowserLanguage(),
                                                  'disable_fallbacks' => true));
         $location = Piwik_UserCountry_LocationProvider::prettyFormatLocation(
@@ -380,7 +386,7 @@ class Piwik_UserCountry_Controller extends Piwik_Controller_Admin
                                                        $APItoCall,
                                                        $defaultDatatableType = null)
     {
-        $view = Piwik_ViewDataTable::factory($defaultDatatableType);
+        $view = ViewDataTable::factory($defaultDatatableType);
         $view->init($this->pluginName, $currentControllerAction, $APItoCall);
         $view->disableExcludeLowPopulation();
 
@@ -427,7 +433,7 @@ class Piwik_UserCountry_Controller extends Piwik_Controller_Admin
             if (!$this->isGeoIPWorking()) {
                 $params = array('module' => 'UserCountry', 'action' => 'adminIndex');
                 $footerMessage .= ' ' . Piwik_Translate('UserCountry_NoDataForGeoIPReport2', array(
-                                                                                                  '<a target="_blank" href="' . Piwik_Url::getCurrentQueryStringWithParametersModified($params) . '">',
+                                                                                                  '<a target="_blank" href="' . Url::getCurrentQueryStringWithParametersModified($params) . '">',
                                                                                                   '</a>',
                                                                                                   '<a target="_blank" href="http://dev.maxmind.com/geoip/geolite?rId=piwik">',
                                                                                                   '</a>'
diff --git a/plugins/UserCountry/GeoIPAutoUpdater.php b/plugins/UserCountry/GeoIPAutoUpdater.php
index dea98daa0f..d981e47b6d 100755
--- a/plugins/UserCountry/GeoIPAutoUpdater.php
+++ b/plugins/UserCountry/GeoIPAutoUpdater.php
@@ -11,6 +11,9 @@
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Date;
+use Piwik\Http;
+use Piwik\Unzip;
+use Piwik\ScheduledTask;
 
 /**
  * Used to automatically update installed GeoIP databases, and manages the updater's
@@ -96,7 +99,7 @@ class Piwik_UserCountry_GeoIPAutoUpdater
 
         // download zipped file to misc dir
         try {
-            $success = Piwik_Http::sendHttpRequest($url, $timeout = 3600, $userAgent = null, $zippedOutputPath);
+            $success = Http::sendHttpRequest($url, $timeout = 3600, $userAgent = null, $zippedOutputPath);
         } catch (Exception $ex) {
             throw new Exception("Piwik_UserCountry_GeoIPAutoUpdater: failed to download '$url' to "
                 . "'$zippedOutputPath': " . $ex->getMessage());
@@ -138,7 +141,7 @@ class Piwik_UserCountry_GeoIPAutoUpdater
         // extract file
         if (substr($path, -7, 7) == '.tar.gz') {
             // find the .dat file in the tar archive
-            $unzip = Piwik_Unzip::factory('tar.gz', $path);
+            $unzip = Unzip::factory('tar.gz', $path);
             $content = $unzip->listContent();
 
             if (empty($content)) {
@@ -172,7 +175,7 @@ class Piwik_UserCountry_GeoIPAutoUpdater
             fwrite($fd, $unzipped);
             fclose($fd);
         } else if (substr($path, -3, 3) == '.gz') {
-            $unzip = Piwik_Unzip::factory('gz', $path);
+            $unzip = Unzip::factory('gz', $path);
             $success = $unzip->extract($outputPath);
 
             if ($success !== true) {
@@ -242,7 +245,7 @@ class Piwik_UserCountry_GeoIPAutoUpdater
     /**
      * Creates a ScheduledTask instance based on set option values.
      *
-     * @return Piwik_ScheduledTask
+     * @return ScheduledTask
      */
     public static function makeScheduledTask()
     {
@@ -264,7 +267,7 @@ class Piwik_UserCountry_GeoIPAutoUpdater
                 break;
         }
 
-        return new Piwik_ScheduledTask($instance, 'update', null, $schedulePeriod, Piwik_ScheduledTask::LOWEST_PRIORITY);
+        return new ScheduledTask($instance, 'update', null, $schedulePeriod, ScheduledTask::LOWEST_PRIORITY);
     }
 
     /**
diff --git a/plugins/UserCountry/LocationProvider.php b/plugins/UserCountry/LocationProvider.php
index 153247a252..5fb24a4dd2 100755
--- a/plugins/UserCountry/LocationProvider.php
+++ b/plugins/UserCountry/LocationProvider.php
@@ -9,6 +9,7 @@
  * @package Piwik_UserCountry
  */
 use Piwik\Common;
+use Piwik\IP;
 
 /**
  * @see plugins/UserCountry/LocationProvider/Default.php
@@ -179,7 +180,7 @@ abstract class Piwik_UserCountry_LocationProvider
      *   'status' - Either self::NOT_INSTALLED, self::INSTALLED or self::BROKEN.
      *   'statusMessage' - If the status is self::BROKEN, then the message describes why.
      *   'location' - A pretty formatted location of the current IP address
-     *                (Piwik_IP::getIpFromHeader()).
+     *                (IP::getIpFromHeader()).
      *
      * An example result:
      * array(
@@ -216,7 +217,7 @@ abstract class Piwik_UserCountry_LocationProvider
                 $workingOrError = $provider->isWorking();
                 if ($workingOrError === true) // if the implementation is configured correctly, get the location
                 {
-                    $locInfo = array('ip'                => Piwik_IP::getIpFromHeader(),
+                    $locInfo = array('ip'                => IP::getIpFromHeader(),
                                      'lang'              => Common::getBrowserLanguage(),
                                      'disable_fallbacks' => true);
 
@@ -439,9 +440,9 @@ abstract class Piwik_UserCountry_LocationProvider
     protected function getIpFromInfo($info)
     {
         $ip = $info['ip'];
-        if (Piwik_IP::isMappedIPv4($ip)) {
-            return Piwik_IP::getIPv4FromMappedIPv6($ip);
-        } else if (Piwik_IP::isIPv6($ip)) // IPv6 is not supported (yet)
+        if (IP::isMappedIPv4($ip)) {
+            return IP::getIPv4FromMappedIPv6($ip);
+        } else if (IP::isIPv6($ip)) // IPv6 is not supported (yet)
         {
             return false;
         } else {
diff --git a/plugins/UserCountry/LocationProvider/GeoIp/ServerBased.php b/plugins/UserCountry/LocationProvider/GeoIp/ServerBased.php
index 382ee9a319..ab3942974f 100755
--- a/plugins/UserCountry/LocationProvider/GeoIp/ServerBased.php
+++ b/plugins/UserCountry/LocationProvider/GeoIp/ServerBased.php
@@ -10,6 +10,7 @@
  */
 
 use Piwik\Common;
+use Piwik\IP;
 
 /**
  * A LocationProvider that uses an GeoIP module installed in an HTTP Server.
@@ -66,7 +67,7 @@ class Piwik_UserCountry_LocationProvider_GeoIp_ServerBased extends Piwik_UserCou
 
         // geoip modules that are built into servers can't use a forced IP. in this case we try
         // to fallback to another version.
-        $myIP = Piwik_IP::getIpFromHeader();
+        $myIP = IP::getIpFromHeader();
         if (!self::isSameOrAnonymizedIp($ip, $myIP)
             && (!isset($info['disable_fallbacks'])
                 || !$info['disable_fallbacks'])
diff --git a/plugins/UserCountry/UserCountry.php b/plugins/UserCountry/UserCountry.php
index 72c7cbda9b..008345a785 100644
--- a/plugins/UserCountry/UserCountry.php
+++ b/plugins/UserCountry/UserCountry.php
@@ -98,10 +98,10 @@ class Piwik_UserCountry extends Plugin
         $widgetCityLabel = Piwik_Translate('UserCountry_WidgetLocation')
             . ' (' . Piwik_Translate('UserCountry_City') . ')';
 
-        Piwik_AddWidget('General_Visitors', $widgetContinentLabel, 'UserCountry', 'getContinent');
-        Piwik_AddWidget('General_Visitors', $widgetCountryLabel, 'UserCountry', 'getCountry');
-        Piwik_AddWidget('General_Visitors', $widgetRegionLabel, 'UserCountry', 'getRegion');
-        Piwik_AddWidget('General_Visitors', $widgetCityLabel, 'UserCountry', 'getCity');
+        WidgetsList::add('General_Visitors', $widgetContinentLabel, 'UserCountry', 'getContinent');
+        WidgetsList::add('General_Visitors', $widgetCountryLabel, 'UserCountry', 'getCountry');
+        WidgetsList::add('General_Visitors', $widgetRegionLabel, 'UserCountry', 'getRegion');
+        WidgetsList::add('General_Visitors', $widgetCityLabel, 'UserCountry', 'getCity');
     }
 
     function addMenu()
diff --git a/plugins/UserCountryMap/Controller.php b/plugins/UserCountryMap/Controller.php
index f9f52e8233..a70e3a83d7 100644
--- a/plugins/UserCountryMap/Controller.php
+++ b/plugins/UserCountryMap/Controller.php
@@ -8,8 +8,12 @@
  * @category Piwik_Plugins
  * @package Piwik_UserCountryMap
  */
+use Piwik\API\Request;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\ViewDataTable;
+use Piwik\View;
 use Piwik\Site;
 use Piwik\Config;
 
@@ -17,7 +21,7 @@ use Piwik\Config;
  *
  * @package Piwik_UserCountryMap
  */
-class Piwik_UserCountryMap_Controller extends Piwik_Controller
+class Piwik_UserCountryMap_Controller extends Controller
 {
 
     // By default plot up to the last 30 days of visitors on the map, for low traffic sites
@@ -34,10 +38,10 @@ class Piwik_UserCountryMap_Controller extends Piwik_Controller
         $date = Common::getRequestVar('date');
         $token_auth = Piwik::getCurrentUserTokenAuth();
 
-        $view = new Piwik_View('@UserCountryMap/visitorMap');
+        $view = new View('@UserCountryMap/visitorMap');
 
         // request visits summary
-        $request = new Piwik_API_Request(
+        $request = new Request(
             'method=VisitsSummary.get&format=PHP'
                 . '&idSite=' . $idSite
                 . '&period=' . $period
@@ -107,7 +111,7 @@ class Piwik_UserCountryMap_Controller extends Piwik_Controller
         Piwik::checkUserHasViewAccess($idSite);
 
         $token_auth = Piwik::getCurrentUserTokenAuth();
-        $view = new Piwik_View('@UserCountryMap/realtimeMap');
+        $view = new View('@UserCountryMap/realtimeMap');
 
         $view->mapIsStandaloneNotWidget = $standalone;
 
@@ -153,7 +157,7 @@ class Piwik_UserCountryMap_Controller extends Piwik_Controller
     {
         $params['format'] = 'json';
         $params['showRawMetrics'] = 1;
-        $segment = Piwik_ViewDataTable::getRawSegmentFromRequest();
+        $segment = ViewDataTable::getRawSegmentFromRequest();
         if(!empty($segment)) {
             $params['segment'] = $segment;
         }
@@ -171,7 +175,7 @@ class Piwik_UserCountryMap_Controller extends Piwik_Controller
 
     private function getMetrics($idSite, $period, $date, $token_auth)
     {
-        $request = new Piwik_API_Request(
+        $request = new Request(
             'method=API.getMetadata&format=PHP'
                 . '&apiModule=UserCountry&apiAction=getCountry'
                 . '&idSite=' . $idSite
@@ -203,7 +207,7 @@ class Piwik_UserCountryMap_Controller extends Piwik_Controller
             . "&period=" . $period
             . "&date=" . $date
             . "&token_auth=" . $token_auth
-            . "&segment=" . Piwik_ViewDataTable::getRawSegmentFromRequest()
+            . "&segment=" . ViewDataTable::getRawSegmentFromRequest()
             . "&enable_filter_excludelowpop=1"
             . "&showRawMetrics=1";
 
diff --git a/plugins/UserCountryMap/UserCountryMap.php b/plugins/UserCountryMap/UserCountryMap.php
index 1659288d1c..ac9255a303 100644
--- a/plugins/UserCountryMap/UserCountryMap.php
+++ b/plugins/UserCountryMap/UserCountryMap.php
@@ -8,6 +8,8 @@
  * @category Piwik_Plugins
  * @package Piwik_UserCountryMap
  */
+use Piwik\FrontController;
+use Piwik\Version;
 use Piwik\Plugin;
 
 /**
@@ -26,14 +28,14 @@ class Piwik_UserCountryMap extends Plugin
             'description'     => 'This plugin provides the widgets Visitor Map and Real-time Map. Note: Requires the UserCountry plugin enabled.',
             'author'          => 'Piwik',
             'author_homepage' => 'http://piwik.org/',
-            'version'         => Piwik_Version::VERSION
+            'version'         => Version::VERSION
         );
     }
 
     public function postLoad()
     {
-        Piwik_AddWidget('General_Visitors', Piwik_Translate('UserCountryMap_VisitorMap'), 'UserCountryMap', 'visitorMap');
-        Piwik_AddWidget('Live!', Piwik_Translate('UserCountryMap_RealTimeMap'), 'UserCountryMap', 'realtimeMap');
+        WidgetsList::add('General_Visitors', Piwik_Translate('UserCountryMap_VisitorMap'), 'UserCountryMap', 'visitorMap');
+        WidgetsList::add('Live!', Piwik_Translate('UserCountryMap_RealTimeMap'), 'UserCountryMap', 'realtimeMap');
 
         Piwik_AddAction('template_leftColumnUserCountry', array('Piwik_UserCountryMap', 'insertMapInLocationReport'));
     }
@@ -41,7 +43,7 @@ class Piwik_UserCountryMap extends Plugin
     static public function insertMapInLocationReport(&$out)
     {
         $out = '<h2>' . Piwik_Translate('UserCountryMap_VisitorMap') . '</h2>';
-        $out .= Piwik_FrontController::getInstance()->fetchDispatch('UserCountryMap', 'visitorMap');
+        $out .= FrontController::getInstance()->fetchDispatch('UserCountryMap', 'visitorMap');
     }
 
     /**
diff --git a/plugins/UserSettings/Archiver.php b/plugins/UserSettings/Archiver.php
index 40f6b94eb3..cdfa858d6e 100644
--- a/plugins/UserSettings/Archiver.php
+++ b/plugins/UserSettings/Archiver.php
@@ -13,6 +13,7 @@ use Piwik\Common;
 use Piwik\DataAccess\LogAggregator;
 use Piwik\Metrics;
 use Piwik\DataTable;
+use Piwik\DataArray;
 use Piwik\PluginsArchiver;
 
 require_once PIWIK_INCLUDE_PATH . '/plugins/UserSettings/functions.php';
@@ -125,7 +126,7 @@ class Piwik_UserSettings_Archiver extends PluginsArchiver
     {
         $query = $this->getLogAggregator()->queryVisitsByDimension( array("label" => self::LANGUAGE_DIMENSION) );
         $languageCodes = array_keys(Common::getLanguagesList());
-        $metricsByLanguage = new Piwik_DataArray();
+        $metricsByLanguage = new DataArray();
         while ($row = $query->fetch()) {
             $code = Common::extractLanguageCodeFromBrowserLanguage($row['label'], $languageCodes);
             $metricsByLanguage->sumMetricsVisits($code, $row);
diff --git a/plugins/UserSettings/Controller.php b/plugins/UserSettings/Controller.php
index 515eacf118..086cd020e7 100644
--- a/plugins/UserSettings/Controller.php
+++ b/plugins/UserSettings/Controller.php
@@ -8,16 +8,19 @@
  * @category Piwik_Plugins
  * @package Piwik_UserSettings
  */
+use Piwik\Controller;
+use Piwik\ViewDataTable;
+use Piwik\View;
 
 /**
  *
  * @package Piwik_UserSettings
  */
-class Piwik_UserSettings_Controller extends Piwik_Controller
+class Piwik_UserSettings_Controller extends Controller
 {
     public function index()
     {
-        $view = new Piwik_View('@UserSettings/index');
+        $view = new View('@UserSettings/index');
 
         $view->dataTablePlugin = $this->getPlugin(true);
         $view->dataTableResolution = $this->getResolution(true);
@@ -33,56 +36,56 @@ class Piwik_UserSettings_Controller extends Piwik_Controller
     
     public function getResolution($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
     
     public function getConfiguration($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getOS($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getOSFamily($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getMobileVsDesktop($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getBrowserVersion($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getBrowser($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getBrowserType($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getWideScreen($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getPlugin($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getLanguage($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 }
diff --git a/plugins/UserSettings/UserSettings.php b/plugins/UserSettings/UserSettings.php
index ce5a37f707..618f8fdfd9 100644
--- a/plugins/UserSettings/UserSettings.php
+++ b/plugins/UserSettings/UserSettings.php
@@ -355,7 +355,7 @@ class Piwik_UserSettings extends Plugin
         foreach ($this->reportMetadata as $report) {
             list($category, $name, $controllerName, $controllerAction) = $report;
             if ($category == false) continue;
-            Piwik_AddWidget($category, $name, $controllerName, $controllerAction);
+            WidgetsList::add($category, $name, $controllerName, $controllerAction);
         }
     }
 
diff --git a/plugins/UsersManager/API.php b/plugins/UsersManager/API.php
index c4c8dc0806..0eeda5be60 100644
--- a/plugins/UsersManager/API.php
+++ b/plugins/UsersManager/API.php
@@ -485,7 +485,7 @@ class Piwik_UsersManager_API
      */
     public function userExists($userLogin)
     {
-        $count = Piwik_FetchOne("SELECT count(*)
+        $count = Db::fetchOne("SELECT count(*)
 													FROM " . Common::prefixTable("user") . "
 													WHERE login = ?", $userLogin);
         return $count != 0;
@@ -500,7 +500,7 @@ class Piwik_UsersManager_API
     public function userEmailExists($userEmail)
     {
         Piwik::checkUserIsNotAnonymous();
-        $count = Piwik_FetchOne("SELECT count(*)
+        $count = Db::fetchOne("SELECT count(*)
 								FROM " . Common::prefixTable("user") . "
 								WHERE email = ?", $userEmail);
         return $count != 0
diff --git a/plugins/UsersManager/Controller.php b/plugins/UsersManager/Controller.php
index 506c6e6acc..9bc778c6ff 100644
--- a/plugins/UsersManager/Controller.php
+++ b/plugins/UsersManager/Controller.php
@@ -8,16 +8,20 @@
  * @category Piwik_Plugins
  * @package Piwik_UsersManager
  */
+use Piwik\API\ResponseBuilder;
+use Piwik\Controller\Admin;
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Config;
+use Piwik\View;
+use Piwik\Url;
 use Piwik\Site;
 
 /**
  *
  * @package Piwik_UsersManager
  */
-class Piwik_UsersManager_Controller extends Piwik_Controller_Admin
+class Piwik_UsersManager_Controller extends Admin
 {
     static function orderByName($a, $b)
     {
@@ -31,7 +35,7 @@ class Piwik_UsersManager_Controller extends Piwik_Controller_Admin
     {
         Piwik::checkUserIsNotAnonymous();
 
-        $view = new Piwik_View('@UsersManager/index');
+        $view = new View('@UsersManager/index');
 
         $IdSitesAdmin = Piwik_SitesManager_API::getInstance()->getSitesIdWithAdminAccess();
         $idSiteSelected = 1;
@@ -123,7 +127,7 @@ class Piwik_UsersManager_Controller extends Piwik_Controller_Admin
     {
         Piwik::checkUserIsNotAnonymous();
 
-        $view = new Piwik_View('@UsersManager/userSettings');
+        $view = new View('@UsersManager/userSettings');
 
         $userLogin = Piwik::getCurrentUserLogin();
         if (Piwik::isUserIsSuperUser()) {
@@ -164,7 +168,7 @@ class Piwik_UsersManager_Controller extends Piwik_Controller_Admin
 
         $view->ignoreCookieSet = Piwik_Tracker_IgnoreCookie::isIgnoreCookieFound();
         $this->initViewAnonymousUserSettings($view);
-        $view->piwikHost = Piwik_Url::getCurrentHost();
+        $view->piwikHost = Url::getCurrentHost();
         $this->setBasicVariablesView($view);
         echo $view->render();
     }
@@ -181,7 +185,7 @@ class Piwik_UsersManager_Controller extends Piwik_Controller_Admin
 
     /**
      * The Super User can modify Anonymous user settings
-     * @param Piwik_View $view
+     * @param View $view
      */
     protected function initViewAnonymousUserSettings($view)
     {
@@ -226,7 +230,7 @@ class Piwik_UsersManager_Controller extends Piwik_Controller_Admin
      */
     public function recordAnonymousUserSettings()
     {
-        $response = new Piwik_API_ResponseBuilder(Common::getRequestVar('format'));
+        $response = new ResponseBuilder(Common::getRequestVar('format'));
         try {
             Piwik::checkUserIsSuperUser();
             $this->checkTokenInUrl();
@@ -253,7 +257,7 @@ class Piwik_UsersManager_Controller extends Piwik_Controller_Admin
      */
     public function recordUserSettings()
     {
-        $response = new Piwik_API_ResponseBuilder(Common::getRequestVar('format'));
+        $response = new ResponseBuilder(Common::getRequestVar('format'));
         try {
             $this->checkTokenInUrl();
 
@@ -275,7 +279,7 @@ class Piwik_UsersManager_Controller extends Piwik_Controller_Admin
             }
 
             // UI disables password change on invalid host, but check here anyway
-            if (!Piwik_Url::isValidHost()
+            if (!Url::isValidHost()
                 && $newPassword !== false
             ) {
                 throw new Exception("Cannot change password with untrusted hostname!");
diff --git a/plugins/UsersManager/UsersManager.php b/plugins/UsersManager/UsersManager.php
index 8d2aeb7a57..3c3b0a761a 100644
--- a/plugins/UsersManager/UsersManager.php
+++ b/plugins/UsersManager/UsersManager.php
@@ -9,6 +9,7 @@
  * @package Piwik_UsersManager
  */
 use Piwik\Piwik;
+use Piwik\Piwik_Option;
 use Piwik\Plugin;
 
 /**
diff --git a/plugins/VisitFrequency/API.php b/plugins/VisitFrequency/API.php
index 08d37c30b2..7e77d561ec 100644
--- a/plugins/VisitFrequency/API.php
+++ b/plugins/VisitFrequency/API.php
@@ -8,6 +8,7 @@
  * @category Piwik_Plugins
  * @package Piwik_VisitFrequency
  */
+use Piwik\API\Request;
 use Piwik\Piwik;
 use Piwik\SegmentExpression;
 
@@ -43,7 +44,7 @@ class Piwik_VisitFrequency_API
             'format'    => 'original',
             'serialize' => 0 // tests set this to 1
         );
-        $table = Piwik_API_Request::processRequest('VisitsSummary.get', $params);
+        $table = Request::processRequest('VisitsSummary.get', $params);
         $this->prefixColumns($table, $period);
         return $table;
     }
diff --git a/plugins/VisitFrequency/Controller.php b/plugins/VisitFrequency/Controller.php
index c9362959cc..77baa6b539 100644
--- a/plugins/VisitFrequency/Controller.php
+++ b/plugins/VisitFrequency/Controller.php
@@ -8,18 +8,21 @@
  * @category Piwik_Plugins
  * @package Piwik_VisitFrequency
  */
+use Piwik\API\Request;
 use Piwik\Piwik;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\View;
 
 /**
  *
  * @package Piwik_VisitFrequency
  */
-class Piwik_VisitFrequency_Controller extends Piwik_Controller
+class Piwik_VisitFrequency_Controller extends Controller
 {
     function index()
     {
-        $view = new Piwik_View('@VisitFrequency/index');
+        $view = new View('@VisitFrequency/index');
         $view->graphEvolutionVisitFrequency = $this->getEvolutionGraph(true, array('nb_visits_returning'));
         $this->setSparklinesAndNumbers($view);
         echo $view->render();
@@ -27,7 +30,7 @@ class Piwik_VisitFrequency_Controller extends Piwik_Controller
 
     public function getSparklines()
     {
-        $view = new Piwik_View('@VisitFrequency/getSparklines');
+        $view = new View('@VisitFrequency/getSparklines');
         $this->setSparklinesAndNumbers($view);
         echo $view->render();
     }
@@ -99,7 +102,7 @@ class Piwik_VisitFrequency_Controller extends Piwik_Controller
     protected function getSummary()
     {
         $requestString = "method=VisitFrequency.get&format=original";
-        $request = new Piwik_API_Request($requestString);
+        $request = new Request($requestString);
         return $request->process();
     }
 }
diff --git a/plugins/VisitFrequency/VisitFrequency.php b/plugins/VisitFrequency/VisitFrequency.php
index ee5c0ecd2a..95586de73e 100644
--- a/plugins/VisitFrequency/VisitFrequency.php
+++ b/plugins/VisitFrequency/VisitFrequency.php
@@ -56,8 +56,8 @@ class Piwik_VisitFrequency extends Plugin
 
     function addWidgets()
     {
-        Piwik_AddWidget('General_Visitors', 'VisitFrequency_WidgetOverview', 'VisitFrequency', 'getSparklines');
-        Piwik_AddWidget('General_Visitors', 'VisitFrequency_WidgetGraphReturning', 'VisitFrequency', 'getEvolutionGraph', array('columns' => array('nb_visits_returning')));
+        WidgetsList::add('General_Visitors', 'VisitFrequency_WidgetOverview', 'VisitFrequency', 'getSparklines');
+        WidgetsList::add('General_Visitors', 'VisitFrequency_WidgetGraphReturning', 'VisitFrequency', 'getEvolutionGraph', array('columns' => array('nb_visits_returning')));
     }
 
     function addMenu()
diff --git a/plugins/VisitTime/Archiver.php b/plugins/VisitTime/Archiver.php
index fd6c1dcc8b..77b7659d9b 100644
--- a/plugins/VisitTime/Archiver.php
+++ b/plugins/VisitTime/Archiver.php
@@ -10,6 +10,7 @@
  */
 
 use Piwik\Date;
+use Piwik\DataArray;
 use Piwik\PluginsArchiver;
 
 class Piwik_VisitTime_Archiver extends PluginsArchiver
@@ -47,7 +48,7 @@ class Piwik_VisitTime_Archiver extends PluginsArchiver
         $this->getProcessor()->insertBlobRecord(self::LOCAL_TIME_RECORD_NAME, $this->getProcessor()->getDataTableFromDataArray($array)->getSerialized());
     }
 
-    protected function convertTimeToLocalTimezone(Piwik_DataArray &$array)
+    protected function convertTimeToLocalTimezone(DataArray &$array)
     {
         $date = Date::factory($this->getProcessor()->getDateStart()->getDateStartUTC())->toString();
         $timezone = $this->getProcessor()->getSite()->getTimezone();
@@ -58,16 +59,16 @@ class Piwik_VisitTime_Archiver extends PluginsArchiver
             $hourInTz = (int)Date::factory($datetime, $timezone)->toString('H');
             $converted[$hourInTz] = $stats;
         }
-        return new Piwik_DataArray($converted);
+        return new DataArray($converted);
     }
 
 
-    private function ensureAllHoursAreSet( Piwik_DataArray &$array)
+    private function ensureAllHoursAreSet( DataArray &$array)
     {
         $data = $array->getDataArray();
         for ($i = 0; $i <= 23; $i++) {
             if (empty($data[$i])) {
-                $array->sumMetricsVisits( $i, Piwik_DataArray::makeEmptyRow());
+                $array->sumMetricsVisits( $i, DataArray::makeEmptyRow());
             }
         }
     }
diff --git a/plugins/VisitTime/Controller.php b/plugins/VisitTime/Controller.php
index 600262625c..1cc2169741 100644
--- a/plugins/VisitTime/Controller.php
+++ b/plugins/VisitTime/Controller.php
@@ -8,16 +8,19 @@
  * @category Piwik_Plugins
  * @package Piwik_VisitTime
  */
+use Piwik\Controller;
+use Piwik\ViewDataTable;
+use Piwik\View;
 
 /**
  *
  * @package Piwik_VisitTime
  */
-class Piwik_VisitTime_Controller extends Piwik_Controller
+class Piwik_VisitTime_Controller extends Controller
 {
     public function index()
     {
-        $view = new Piwik_View('@VisitTime/index');
+        $view = new View('@VisitTime/index');
         $view->dataTableVisitInformationPerLocalTime = $this->getVisitInformationPerLocalTime(true);
         $view->dataTableVisitInformationPerServerTime = $this->getVisitInformationPerServerTime(true);
         echo $view->render();
@@ -25,16 +28,16 @@ class Piwik_VisitTime_Controller extends Piwik_Controller
 
     public function getVisitInformationPerServerTime($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getVisitInformationPerLocalTime($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 
     public function getByDayOfWeek($fetch = false)
     {
-        return Piwik_ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
+        return ViewDataTable::render($this->pluginName, __FUNCTION__, $fetch);
     }
 }
diff --git a/plugins/VisitTime/VisitTime.php b/plugins/VisitTime/VisitTime.php
index 4d73dd8ae0..d654eeb947 100644
--- a/plugins/VisitTime/VisitTime.php
+++ b/plugins/VisitTime/VisitTime.php
@@ -76,9 +76,9 @@ class Piwik_VisitTime extends Plugin
 
     function addWidgets()
     {
-        Piwik_AddWidget('VisitsSummary_VisitsSummary', 'VisitTime_WidgetLocalTime', 'VisitTime', 'getVisitInformationPerLocalTime');
-        Piwik_AddWidget('VisitsSummary_VisitsSummary', 'VisitTime_WidgetServerTime', 'VisitTime', 'getVisitInformationPerServerTime');
-        Piwik_AddWidget('VisitsSummary_VisitsSummary', 'VisitTime_VisitsByDayOfWeek', 'VisitTime', 'getByDayOfWeek');
+        WidgetsList::add('VisitsSummary_VisitsSummary', 'VisitTime_WidgetLocalTime', 'VisitTime', 'getVisitInformationPerLocalTime');
+        WidgetsList::add('VisitsSummary_VisitsSummary', 'VisitTime_WidgetServerTime', 'VisitTime', 'getVisitInformationPerServerTime');
+        WidgetsList::add('VisitsSummary_VisitsSummary', 'VisitTime_VisitsByDayOfWeek', 'VisitTime', 'getByDayOfWeek');
     }
 
     function addMenu()
diff --git a/plugins/VisitorGenerator/Controller.php b/plugins/VisitorGenerator/Controller.php
index 1a4f9facd0..f0275b3348 100644
--- a/plugins/VisitorGenerator/Controller.php
+++ b/plugins/VisitorGenerator/Controller.php
@@ -9,16 +9,22 @@
  * @package Piwik_VisitorGenerator
  */
 use Piwik\ArchiveProcessor\Rules;
+use Piwik\Controller\Admin;
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\Date;
+use Piwik\Http;
+use Piwik\Nonce;
+use Piwik\View;
+use Piwik\Url;
+use Piwik\Timer;
 use Piwik\Site;
 
 /**
  *
  * @package Piwik_VisitorGenerator
  */
-class Piwik_VisitorGenerator_Controller extends Piwik_Controller_Admin
+class Piwik_VisitorGenerator_Controller extends Admin
 {
     public function index()
     {
@@ -26,10 +32,10 @@ class Piwik_VisitorGenerator_Controller extends Piwik_Controller_Admin
 
         $sitesList = Piwik_SitesManager_API::getInstance()->getSitesWithAdminAccess();
 
-        $view = new Piwik_View('@VisitorGenerator/index');
+        $view = new View('@VisitorGenerator/index');
         $this->setBasicVariablesView($view);
         $view->assign('sitesList', $sitesList);
-        $view->nonce = Piwik_Nonce::getNonce('Piwik_VisitorGenerator.generate');
+        $view->nonce = Nonce::getNonce('Piwik_VisitorGenerator.generate');
         $view->countActionsPerRun = count($this->getAccessLog());
         $view->accessLogPath = $this->getAccessLogPath();
         echo $view->render();
@@ -51,11 +57,11 @@ class Piwik_VisitorGenerator_Controller extends Piwik_Controller_Admin
         Piwik::checkUserIsSuperUser();
         $nonce = Common::getRequestVar('form_nonce', '', 'string', $_POST);
         if (Common::getRequestVar('choice', 'no') != 'yes' ||
-            !Piwik_Nonce::verifyNonce('Piwik_VisitorGenerator.generate', $nonce)
+            !Nonce::verifyNonce('Piwik_VisitorGenerator.generate', $nonce)
         ) {
             Piwik::redirectToModule('VisitorGenerator', 'index');
         }
-        Piwik_Nonce::discardNonce('Piwik_VisitorGenerator.generate');
+        Nonce::discardNonce('Piwik_VisitorGenerator.generate');
 
         $daysToCompute = Common::getRequestVar('daysToCompute', 1, 'int');
 
@@ -65,7 +71,7 @@ class Piwik_VisitorGenerator_Controller extends Piwik_Controller_Admin
 
         Piwik::setMaxExecutionTime(0);
 
-        $timer = new Piwik_Timer;
+        $timer = new Timer;
         $time = time() - ($daysToCompute - 1) * 86400;
 
         $nbActionsTotal = 0;
@@ -83,7 +89,7 @@ class Piwik_VisitorGenerator_Controller extends Piwik_Controller_Admin
         $browserArchiving = Rules::isBrowserTriggerEnabled();
 
         // Init view
-        $view = new Piwik_View('@VisitorGenerator/generate');
+        $view = new View('@VisitorGenerator/generate');
         $this->setBasicVariablesView($view);
         $view->assign('browserArchivingEnabled', $browserArchiving);
         $view->assign('timer', $timer);
@@ -114,7 +120,7 @@ class Piwik_VisitorGenerator_Controller extends Piwik_Controller_Admin
             "fr-ch",
             "fr",
         );
-        $prefix = Piwik_Url::getCurrentUrlWithoutFileName() . "piwik.php";
+        $prefix = Url::getCurrentUrlWithoutFileName() . "piwik.php";
         $count = 0;
         foreach ($logs as $log) {
             if (!preg_match('/^(\S+) \S+ \S+ \[(.*?)\] "GET (\S+.*?)" \d+ \d+ "(.*?)" "(.*?)"/', $log, $m)) {
@@ -150,7 +156,7 @@ class Piwik_VisitorGenerator_Controller extends Piwik_Controller_Admin
 
             $acceptLanguage = $acceptLanguages[$count % count($acceptLanguages)];
 
-            if ($output = Piwik_Http::sendHttpRequest($url, $timeout = 5, $ua, $path = null, $follow = 0, $acceptLanguage)) {
+            if ($output = Http::sendHttpRequest($url, $timeout = 5, $ua, $path = null, $follow = 0, $acceptLanguage)) {
                 $count++;
             }
         }
diff --git a/plugins/VisitorInterest/Controller.php b/plugins/VisitorInterest/Controller.php
index cecb7fd61c..b3a658f5c8 100644
--- a/plugins/VisitorInterest/Controller.php
+++ b/plugins/VisitorInterest/Controller.php
@@ -9,15 +9,18 @@
  * @package Piwik_VisitorInterest
  */
 use Piwik\Metrics;
+use Piwik\Controller;
+use Piwik\ViewDataTable;
+use Piwik\View;
 
 /**
  * @package Piwik_VisitorInterest
  */
-class Piwik_VisitorInterest_Controller extends Piwik_Controller
+class Piwik_VisitorInterest_Controller extends Controller
 {
     public function index()
     {
-        $view = new Piwik_View('@VisitorInterest/index');
+        $view = new View('@VisitorInterest/index');
         $view->dataTableNumberOfVisitsPerVisitDuration = $this->getNumberOfVisitsPerVisitDuration(true);
         $view->dataTableNumberOfVisitsPerPage = $this->getNumberOfVisitsPerPage(true);
         $view->dataTableNumberOfVisitsByVisitNum = $this->getNumberOfVisitsByVisitCount(true);
@@ -27,7 +30,7 @@ class Piwik_VisitorInterest_Controller extends Piwik_Controller
 
     public function getNumberOfVisitsPerVisitDuration($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory('cloud');
+        $view = ViewDataTable::factory('cloud');
         $view->init($this->pluginName, __FUNCTION__, "VisitorInterest.getNumberOfVisitsPerVisitDuration");
 
         $view->setColumnsToDisplay(array('label', 'nb_visits'));
@@ -45,7 +48,7 @@ class Piwik_VisitorInterest_Controller extends Piwik_Controller
 
     public function getNumberOfVisitsPerPage($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory('cloud');
+        $view = ViewDataTable::factory('cloud');
         $view->init($this->pluginName, __FUNCTION__, "VisitorInterest.getNumberOfVisitsPerPage");
         $view->setColumnsToDisplay(array('label', 'nb_visits'));
         $view->setSortedColumn('label', 'asc');
@@ -69,7 +72,7 @@ class Piwik_VisitorInterest_Controller extends Piwik_Controller
      */
     public function getNumberOfVisitsByVisitCount($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__, "VisitorInterest.getNumberOfVisitsByVisitCount");
         $view->setColumnsToDisplay(array('label', 'nb_visits', 'nb_visits_percentage'));
         $view->setSortedColumn('label', 'asc');
@@ -95,7 +98,7 @@ class Piwik_VisitorInterest_Controller extends Piwik_Controller
      */
     public function getNumberOfVisitsByDaysSinceLast($fetch = false)
     {
-        $view = Piwik_ViewDataTable::factory();
+        $view = ViewDataTable::factory();
         $view->init($this->pluginName, __FUNCTION__, 'VisitorInterest.getNumberOfVisitsByDaysSinceLast');
         $view->setColumnsToDisplay(array('label', 'nb_visits'));
         $view->setSortedColumn('label', 'asc');
diff --git a/plugins/VisitorInterest/VisitorInterest.php b/plugins/VisitorInterest/VisitorInterest.php
index a503253e1c..12cc0b79c1 100644
--- a/plugins/VisitorInterest/VisitorInterest.php
+++ b/plugins/VisitorInterest/VisitorInterest.php
@@ -9,6 +9,7 @@
  * @package Piwik_VisitorInterest
  */
 use Piwik\ArchiveProcessor;
+use Piwik\FrontController;
 use Piwik\Plugin;
 
 /**
@@ -95,10 +96,10 @@ class Piwik_VisitorInterest extends Plugin
 
     function addWidgets()
     {
-        Piwik_AddWidget('General_Visitors', 'VisitorInterest_WidgetLengths', 'VisitorInterest', 'getNumberOfVisitsPerVisitDuration');
-        Piwik_AddWidget('General_Visitors', 'VisitorInterest_WidgetPages', 'VisitorInterest', 'getNumberOfVisitsPerPage');
-        Piwik_AddWidget('General_Visitors', 'VisitorInterest_visitsByVisitCount', 'VisitorInterest', 'getNumberOfVisitsByVisitCount');
-        Piwik_AddWidget('General_Visitors', 'VisitorInterest_WidgetVisitsByDaysSinceLast', 'VisitorInterest', 'getNumberOfVisitsByDaysSinceLast');
+        WidgetsList::add('General_Visitors', 'VisitorInterest_WidgetLengths', 'VisitorInterest', 'getNumberOfVisitsPerVisitDuration');
+        WidgetsList::add('General_Visitors', 'VisitorInterest_WidgetPages', 'VisitorInterest', 'getNumberOfVisitsPerPage');
+        WidgetsList::add('General_Visitors', 'VisitorInterest_visitsByVisitCount', 'VisitorInterest', 'getNumberOfVisitsByVisitCount');
+        WidgetsList::add('General_Visitors', 'VisitorInterest_WidgetVisitsByDaysSinceLast', 'VisitorInterest', 'getNumberOfVisitsByDaysSinceLast');
     }
 
     function addMenu()
@@ -139,7 +140,7 @@ class Piwik_VisitorInterest extends Plugin
         $out = '</div>
 			<div id="rightcolumn">
 			';
-        $out .= Piwik_FrontController::getInstance()->fetchDispatch('VisitorInterest', 'index');
+        $out .= FrontController::getInstance()->fetchDispatch('VisitorInterest', 'index');
         $out .= '</div>';
     }
 }
diff --git a/plugins/VisitsSummary/Controller.php b/plugins/VisitsSummary/Controller.php
index bc30a1e6aa..fc32e77e9e 100644
--- a/plugins/VisitsSummary/Controller.php
+++ b/plugins/VisitsSummary/Controller.php
@@ -8,21 +8,25 @@
  * @category Piwik_Plugins
  * @package Piwik_VisitsSummary
  */
+use Piwik\API\Request;
 use Piwik\DataTable\Row;
 use Piwik\Piwik;
 use Piwik\Common;
 use Piwik\DataTable;
+use Piwik\Controller;
+use Piwik\ViewDataTable;
+use Piwik\View;
 use Piwik\Site;
 
 /**
  *
  * @package Piwik_VisitsSummary
  */
-class Piwik_VisitsSummary_Controller extends Piwik_Controller
+class Piwik_VisitsSummary_Controller extends Controller
 {
     public function index()
     {
-        $view = new Piwik_View('@VisitsSummary/index');
+        $view = new View('@VisitsSummary/index');
         $this->setPeriodVariablesView($view);
         $view->graphEvolutionVisitsSummary = $this->getEvolutionGraph(true, array('nb_visits'));
         $this->setSparklinesAndNumbers($view);
@@ -31,7 +35,7 @@ class Piwik_VisitsSummary_Controller extends Piwik_Controller
 
     public function getSparklines()
     {
-        $view = new Piwik_View('@VisitsSummary/getSparklines');
+        $view = new View('@VisitsSummary/getSparklines');
         $this->setPeriodVariablesView($view);
         $this->setSparklinesAndNumbers($view);
         echo $view->render();
@@ -98,7 +102,7 @@ class Piwik_VisitsSummary_Controller extends Piwik_Controller
             // we disable filters for example "search for pattern", in the case this method is called
             // by a method that already calls the API with some generic filters applied
             "&disable_generic_filters=1";
-        $request = new Piwik_API_Request($requestString);
+        $request = new Request($requestString);
         $result = $request->process();
         return empty($result) ? new DataTable() : $result;
     }
@@ -108,7 +112,7 @@ class Piwik_VisitsSummary_Controller extends Piwik_Controller
         $requestString = "method=VisitsSummary.getVisits" .
             "&format=original" .
             "&disable_generic_filters=1";
-        $request = new Piwik_API_Request($requestString);
+        $request = new Request($requestString);
         return $request->process();
     }
 
@@ -134,7 +138,7 @@ class Piwik_VisitsSummary_Controller extends Piwik_Controller
         $dataTableVisit = self::getVisitsSummary();
         $dataRow = $dataTableVisit->getRowsCount() == 0 ? new Row() : $dataTableVisit->getFirstRow();
 
-        $dataTableActions = Piwik_Actions_API::getInstance()->get($idSite, Common::getRequestVar('period'), Common::getRequestVar('date'), Piwik_ViewDataTable::getRawSegmentFromRequest());
+        $dataTableActions = Piwik_Actions_API::getInstance()->get($idSite, Common::getRequestVar('period'), Common::getRequestVar('date'), ViewDataTable::getRawSegmentFromRequest());
         $dataActionsRow =
             $dataTableActions->getRowsCount() == 0 ? new Row() : $dataTableActions->getFirstRow();
 
diff --git a/plugins/VisitsSummary/VisitsSummary.php b/plugins/VisitsSummary/VisitsSummary.php
index fec9352492..70da748a5e 100644
--- a/plugins/VisitsSummary/VisitsSummary.php
+++ b/plugins/VisitsSummary/VisitsSummary.php
@@ -58,9 +58,9 @@ class Piwik_VisitsSummary extends Plugin
 
     function addWidgets()
     {
-        Piwik_AddWidget('VisitsSummary_VisitsSummary', 'VisitsSummary_WidgetLastVisits', 'VisitsSummary', 'getEvolutionGraph', array('columns' => array('nb_visits')));
-        Piwik_AddWidget('VisitsSummary_VisitsSummary', 'VisitsSummary_WidgetVisits', 'VisitsSummary', 'getSparklines');
-        Piwik_AddWidget('VisitsSummary_VisitsSummary', 'VisitsSummary_WidgetOverviewGraph', 'VisitsSummary', 'index');
+        WidgetsList::add('VisitsSummary_VisitsSummary', 'VisitsSummary_WidgetLastVisits', 'VisitsSummary', 'getEvolutionGraph', array('columns' => array('nb_visits')));
+        WidgetsList::add('VisitsSummary_VisitsSummary', 'VisitsSummary_WidgetVisits', 'VisitsSummary', 'getSparklines');
+        WidgetsList::add('VisitsSummary_VisitsSummary', 'VisitsSummary_WidgetOverviewGraph', 'VisitsSummary', 'index');
     }
 
     function addMenu()
diff --git a/plugins/Widgetize/Controller.php b/plugins/Widgetize/Controller.php
index dad2506936..c7e80a2464 100644
--- a/plugins/Widgetize/Controller.php
+++ b/plugins/Widgetize/Controller.php
@@ -8,25 +8,29 @@
  * @category Piwik_Plugins
  * @package Piwik_Widgetize
  */
+use Piwik\API\Request;
 use Piwik\Common;
+use Piwik\Controller;
+use Piwik\FrontController;
+use Piwik\View;
 
 /**
  *
  * @package Piwik_Widgetize
  */
-class Piwik_Widgetize_Controller extends Piwik_Controller
+class Piwik_Widgetize_Controller extends Controller
 {
     public function index()
     {
-        $view = new Piwik_View('@Widgetize/index');
-        $view->availableWidgets = Common::json_encode(Piwik_GetWidgetsList());
+        $view = new View('@Widgetize/index');
+        $view->availableWidgets = Common::json_encode(WidgetsList::get());
         $this->setGeneralVariablesView($view);
         echo $view->render();
     }
 
     public function testJsInclude1()
     {
-        $view = new Piwik_View('@Widgetize/testJsInclude1');
+        $view = new View('@Widgetize/testJsInclude1');
         $view->url1 = '?module=Widgetize&action=js&moduleToWidgetize=UserSettings&actionToWidgetize=getBrowser&idSite=1&period=day&date=yesterday';
         $view->url2 = '?module=Widgetize&action=js&moduleToWidgetize=API&actionToWidgetize=index&method=ExamplePlugin.getGoldenRatio&format=original';
         echo $view->render();
@@ -34,7 +38,7 @@ class Piwik_Widgetize_Controller extends Piwik_Controller
 
     public function testJsInclude2()
     {
-        $view = new Piwik_View('@Widgetize/testJsInclude2');
+        $view = new View('@Widgetize/testJsInclude2');
         $view->url1 = '?module=Widgetize&action=js&moduleToWidgetize=UserSettings&actionToWidgetize=getBrowser&idSite=1&period=day&date=yesterday';
         $view->url2 = '?module=Widgetize&action=js&moduleToWidgetize=UserCountry&actionToWidgetize=getCountry&idSite=1&period=day&date=yesterday&viewDataTable=cloud&show_footer=0';
         $view->url3 = '?module=Widgetize&action=js&moduleToWidgetize=Referers&actionToWidgetize=getKeywords&idSite=1&period=day&date=yesterday&viewDataTable=table&show_footer=0';
@@ -43,16 +47,16 @@ class Piwik_Widgetize_Controller extends Piwik_Controller
 
     public function iframe()
     {
-        Piwik_API_Request::reloadAuthUsingTokenAuth();
+        Request::reloadAuthUsingTokenAuth();
         $this->init();
         $controllerName = Common::getRequestVar('moduleToWidgetize');
         $actionName = Common::getRequestVar('actionToWidgetize');
         $parameters = array($fetch = true);
-        $outputDataTable = Piwik_FrontController::getInstance()->fetchDispatch($controllerName, $actionName, $parameters);
+        $outputDataTable = FrontController::getInstance()->fetchDispatch($controllerName, $actionName, $parameters);
         if ($controllerName == 'Dashboard' && $actionName == 'index') {
-            $view = new Piwik_View('@Widgetize/iframe_empty');
+            $view = new View('@Widgetize/iframe_empty');
         } else {
-            $view = new Piwik_View('@Widgetize/iframe');
+            $view = new View('@Widgetize/iframe');
         }
         $this->setGeneralVariablesView($view);
         $view->setXFrameOptions('allow');