FlightGear Flight Simulator: free open-source multiplatform flight sim
GLScene Engine for Delphi & C++Builder VCL Windows 32/64
CIRT - CUDA Interactive Ray Tracer
Support for legacy OpenGL in core profiles
C++ Frontend for the RenderMan Interface
Rayshade raytracer
Tao3D is a programming language for real-time interactive 3D
3D .NET engine for Windows, Linux, Mac
Pear3DEngine is a modern and modular 3D development framework
Multi-Language Wrapper Collection for the Irrlicht Engine
loadmd2_chung is a dll to load 3D md2 models into openGL
Bruno's RAY Tracing Engine