Update: I muddled up two mods with similar names, so have now updated this story accordingly. Thanks to hayshed in the comments for pointing out my mistake!
The creators of Minecraft server Civcraft have announced Praxis, a standalone game that plays with the same concepts as its forebear. Civcraft is an anarchy-server that runs a set of server-side mods designed as an “experiment for communities, political ideologies, debate and discussion,” meant to foster an experience “not just about surviving the elements, but about surviving each other, where players can work together to create and shape civilization or to watch it crumble. A world open to any idea, manifesto or philosophy, created by the players.” Which sounds pretty fascinating.
The standalone game will offer all of the same experiences, but on a purpose-built engine, as explained in an announcement post on the Civcraft subreddit.