Dark Metal has been a MUSH (Multi-User Shared Hallucination) since the mid-1990s (and before that, it was a BBS).

A MUSH is a collection of interlinked chatrooms, each room representing a location in the game world.  Players create characters, move from room to room, and participate in text-based roleplay.  There are tools to track stats, roll dice, vehicles to drive-- and fly-- and more elaborate toys.  (You can build your own!)