https://github.com/horde3d/Horde3D
Multi-Language Wrapper Collection for the Irrlicht Engine
3d printing software
Free vector,quaternion,matrix math library
PixelLight is a cross-platform application framework
Megalui: 2D/3D OpenGL & C/C++ Library for Scientific Visualizations
In-flight navigation (and more) for private pilots (Linux).
Displays your photos on the walls of a maze
A 3D rendering / entity engine
osGraphX is a 3D file viewer based on openscenegraph.
A C++ library to easily create GUI-editable objects
Bruno's RAY Tracing Engine
Obsolete: use https://github.com/VMML/vmmlib
An application for analytic geometry education