s&box is a modern game engine, built on Valve's Source 2
Open source library for creative expression on the web, desktop, etc.
Gideros Release version
An OpenGL RTS game engine written in C
FlightGear Flight Simulator: free open-source multiplatform flight sim
An open-source Phantasy Star Online server for *nix
A fun realistic multiplayer free-and-open-source first-person-shooter!
A network server for the flightgear simulator
Major League Baseball Simulation
GameServer is a sophisticated, game server designed for online games
A Sudoko Solver/Puzzle Generator For MS Windows
Motor de juegos de aventura programable
SRCP system daemon
MUD server, based on CircleMUD code, russificated
2D Open Source MMORPG
Neuinterpretation des Adventures von C. Seibt für den Sinclair ZX-81
Molecular viewer and prototyping framework
DIS(IEEE 1278.1) Fully Implemented in C++
MIT Licensed Open Source version of Torque3D from GarageGames
An ASI plugin for Grand Theft Auto V
turn-based wargame/simulator