RetroArch is a frontend for emulators, game engines and media players.
A dead simple 2D game engine for Go
A lightweight game server framework implemented with Actor Model
Open source simulation game based on Transport Tycoon Deluxe
Android, UIQ 3.0, Series 60 Edition 5 open-source software
A lightweight online game framework
Descent 3 by Outrage Entertainment
Gideros Release version
TKD Scoring Wi-Fi Server supporting Android and IPhone clients
SRCP system daemon
A promising chess program
Domination is a game that is a bit like the board game Risk
3D Engine c++
GemRB is a portable open-source implementation of the Infinity Engine
A MUD client for Android, iOS, Linux, Mac OS X and Windows
Arianne is an engine to develop multiplayer online games like Stendhal
The ultimate cataloguer
Computer opponent for the board game Blokus.
Odamex is a free, cross-platform, modern client-server Doom engine
INSTEAD - Simple Text Adventure Interpreter.