A simple 3D framework in C++
Tao3D is a programming language for real-time interactive 3D
Gphoton in a simple 3d modeler and ray tracer.
3D .NET engine for Windows, Linux, Mac
Pear3DEngine is a modern and modular 3D development framework
A Lightweighted Toolkit For Volume Rendering
C++ class library for programming interactive 3D graphics with OpenGL