This program uses code from various sources. These are the licenses:

* New code is licensed under the GPL license v2 or later. 
* BVH building and traversal code is licensed under Apache License v2.
* Approximate Catmull Clark subdivision code is licensed under the MIT license.
* Open Shading Language code on GPU is licensed under the Modified BSD license.
* Sobol direction vectors are licensed under the Modified BSD license.
* Matrix code adapted from OpenEXR under the Modified BSD license.
* Procedural texture functions from Blender are licensed under GPL v2 or later.