https://github.com/horde3d/Horde3D
A continuation of the abandoned Tao Framework project.
Collections of abstractions for Pure Data
XNavigator is a Virtual Earth browser and viewer for http://osm-3d.org
Multi-Language Wrapper Collection for the Irrlicht Engine
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.