Open Source MMORPG Framework
Source of Mana is a unique 2D MMORPG
Arianne is an engine to develop multiplayer online games like Stendhal
An open-source Phantasy Star Online server for *nix
A multiplatform medieval 3D MMORPG
Makes running a PSO server on Linux easier
Free MMORPG
An OpenGL client-server game
Collection of Tools for Perfect World MMORPG
Massively multiplayer online game server and client framework
Python classes to work with Blizzards API
Blender port of Ryzom art data
Open source server for Other Life/Eternal Lands client
The original Xivio.com World Server Core
Open Source Virtual World and MMOG Development Platform
PHP-Nuke modified version