A fun realistic multiplayer free-and-open-source first-person-shooter!
GameServer is a sophisticated, game server designed for online games
MIT Licensed Open Source version of Torque3D from GarageGames
Mini game engine for games104
The Atomic Game Engine is a multi-platform 2D and 3D engine
Design and Display Happy Cube solutions
Automatic chooser of optimal fleet (with limits) for Ogame
A 3D Linac Simulation.
a realtime graphics library
PixelLight is a cross-platform application framework
DREAM is an Open Source GCS