A C++ 3D game engine.
XNA based game engine completely written in c#
A world editor for HGE game engine written in python and uses OpenGL.
A cross-platform game framework based on OpenGL and GObject.
3D game engine for C and C++
3D world editor for game development
Pear3DEngine is a modern and modular 3D development framework
Multi-Language Wrapper Collection for the Irrlicht Engine
Game engine supporting many 3D/2D formats and graphic effects