AMOS BASIC reimplementation in Java
Game framework on top of Python, Panda3D and Twisted
Tween for Torque
A cross platform 3d c++ game engine
The Lambda-Engine is a cross platform game engine.
A DirectX based graphics/physics engine
Basic real-time simulation engine in C++
DREAM is an Open Source GCS
A simple WinAPI game engine
Make games with Lego-like building blocks