3D Without Boundaries
Open Source Solid Modeling CAD
C++ header-only library that simulates GLSL math
A processing system for 3D triangular meshes
Texture font for OpenGL applications
Pear3DEngine is a modern and modular 3D development framework
Multi-Language Wrapper Collection for the Irrlicht Engine
Obsolete: use https://github.com/VMML/vmmlib