Open Source MMORPG Framework
Arianne is an engine to develop multiplayer online games like Stendhal
GameServer is a sophisticated, game server designed for online games
An OpenGL client-server game
starrydb is game server engine
Massively multiplayer online game server and client framework
The original Xivio.com World Server Core
Open Source Virtual World and MMOG Development Platform
Modular Minecraft server plugin - commands, events, ...
Site Woo & Wotlk
Character Database Script for Websites