This is the README for PuTTY, a free Windows and Unix Telnet and SSH client. PuTTY is built using CMake . To compile in the simplest way (on any of Linux, Windows or Mac), run these commands in the source directory: cmake . cmake --build . Then, to install in the simplest way on Linux or Mac: cmake --build . --target install On Unix, pterm would like to be setuid or setgid, as appropriate, to permit it to write records of user logins to /var/run/utmp and /var/log/wtmp. (Of course it will not use this privilege for anything else, and in particular it will drop all privileges before starting up complex subsystems like GTK.) The cmake install step doesn't attempt to add these privileges, so if you want user login recording to work, you should manually ch{own,grp} and chmod the pterm binary yourself after installation. If you don't do this, pterm will still work, but not update the user login databases. Documentation (in various formats including Windows Help and Unix `man' pages) is built from the Halibut (`.but') files in the `doc' subdirectory. If you aren't using one of our source snapshots, you'll need to do this yourself. Halibut can be found at . The PuTTY home web site is https://www.chiark.greenend.org.uk/~sgtatham/putty/ If you want to send bug reports or feature requests, please read the Feedback section of the web site before doing so. Sending one-line reports saying `it doesn't work' will waste your time as much as ours. See the file LICENCE for the licence conditions.