Opensource Created Custom Viewers For Virtual Worlds like SecondLife.
Cooperative multiplayer graphical RPG and adventure game
0 A.D. is a free, open-source, cross-platform real-time strategy game.
Odamex is a free, cross-platform, modern client-server Doom engine
A 2D multiplayer space shooter game
GameServer is a sophisticated, game server designed for online games
Combat Flight Simulator for LINUX. WW2. Network and VOIP. Open-source.
Cross-platform real-time strategy game (3D)
Out battleship is back. Destroy everything in the space!
An online multiplayer real time strategy game
An open-source, multiplayer fps based on Cube 2 Engine.
A minimalist multiplayer game inspired by Astro Party, for Windows.
Clone of Urban Assault with new Graphics.
Grepolis utility
OpenKore is an automation tool for Ragnarok Online
MMOG Framework. Starting place to build a game.
A fast paced simple two player fighting game.