Minimalist 3D Scenegraph Management Framework
Free vector,quaternion,matrix math library
Multi-Language Wrapper Collection for the Irrlicht Engine
Megalui: 2D/3D OpenGL & C/C++ Library for Scientific Visualizations
A 3D rendering / entity engine
A C++ library to easily create GUI-editable objects
Obsolete: use https://github.com/VMML/vmmlib