Arianne is an engine to develop multiplayer online games like Stendhal
Event driven concurrent framework for Python
Asphyre is a cross-platform framework for Delphi and FreePascal.
3D .NET engine for Windows, Linux, Mac
evolution for vegastrike SpaceSim/Combat/Trade game
AutoTeach makes kids study and learn in exchange for internet access.
A multiplatform game engine for interactive fiction experiences
Pear3DEngine is a modern and modular 3D development framework
An extensible development framework for roleplay games.
DiaT is a Textadventure
Game framework on top of Python, Panda3D and Twisted
The Lambda-Engine is a cross platform game engine.
Atlarius is no longer under development.