Arianne is an engine to develop multiplayer online games like Stendhal
...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.
The phoenix kit is a collection of tools & working samples to create cross platform role playing games(RPG) of various types including massively multi-player online role playing games (MMORPG).