You can see the Metacosm framework as a generic way to create an online multiplayer RPG in a persistent world. It is independent of any game rule.
The Metacosm framework provides:
the server (network connections, protocol)
the world persistence
the administration module
the schedule system
the perceptions system
the Interactions system (Actions)
the Entities system (Properties, Influences)
the game time
the game space (Places)
the random generator
the Quests system
the game editors: ActionsEditor, EntitiesEditor and QuestsEditor
some generic clients (text, 2D, 3D).