A project that has moved to GitHub
PyMOL is an OpenGL based molecular visualization system
3D rendering and scene graph library (moved to GitHub)
A raytracing framework for optical/non-optical physics simulations
Pear3DEngine is a modern and modular 3D development framework
Game engine supporting many 3D/2D formats and graphic effects
1st 3D game engine built in C# for .NET, Visual3D Engine's predecessor