Arianne is an engine to develop multiplayer online games like Stendhal
...The engine Marauroa provides a simple way of creating games on a portable and robust server architecture. Marauroa manages the client server communication and provides an object orientated view of the world for game developers. It handles database access in a transparent way to store player accounts, character progress and the state of the world
GameServer is a sophisticated, game server designed for online games
GameServer is a sophisticated, game server designed for massively multiplayer online games. Built with a C++ core and extensible Python scripting, it provides solution for managing persistent game worlds with real-time player interactions, advanced networking, and comprehensive monitoring capabilities.
Modo is a cross-platform online game server and community tool similar in functionality to Valve's Steam platform. The Modo Client is being designed for ease of use and when released, will be free to use by anyone.