MMO that lets players run servers and change the rules

Civcraft is a particularly interesting example of the DIY MMO culture spawned by Minecraft. It’s a game that’s run like an open-source project, in which the admins are constantly accepting patches and new feature code directly from the player base. There are even forks of the server, to experiment with different rules and mechanics and maybe merge them back into the main server.

The game itself is a socio-political sandbox experiment, so goals, challenges and conflict are wholly constructed by the interaction of players in the world. On almost every level it’s a game that’s created by its players.