Odamex is a free, cross-platform, modern client-server Doom engine
0 A.D. is a free, open-source, cross-platform real-time strategy game.
mGSTEP port of the Cube game engine
A fun realistic multiplayer free-and-open-source first-person-shooter!
An open-source, multiplayer fps based on Cube 2 Engine.
C/C++ , PHP, PYTHON, 3D ENGINES, CHROME NATIVE CLIENT
starrydb is game server engine
Clone of Urban Assault with new Graphics.
Your death sentence awaits...
3D FPS Digital Paintball 3 Multiplayer Online Game
Library for creating turn-based games with simultaneous moves.
Mighty 34th century meka action from TeamXbow
A minecraft clone thing on the cube 2 engine
A Co-op/Deathmatch Mod for half-life 2
A 3D multiplayer RPG based in the world of Khoras.
Just Another Generic Shooter