Liquid is a tool for translating Maya scenes into another renderer's scene description. Various RenderMan-compliant renderers are supported. For more information please see the project homepage.
The Virtual Environment Software Sandbox (VESS) is a suite of libraries for developing virtual reality applications in a portable manner with classes for many tracking devices, a simplified "scene graph", a set of "motion models" and audio support. Please note that all support has been moved to GitHub at https://github.com/ucfistirl/vess.