Dark Metal has been a MUSH (Multi-User Shared Hallucination) since the early 1990s.
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!)
This particular MUSH is based on the White Wolf Old World of Darkness theme (revised edition, don't ask which one, we're sort of fuzzy on that ourselves), set in LATMA: a cyberpunk, post-apocalyptic version of Los Angeles and the surrounding territories. We support many of the OWoD systems, including Vampire, Werewolf (Garou, Bastet, Corax, Ratkin), Mage, Mortal+ (Sorcerers/Psychics), and humans (sometimes arguably, depending on their level of cybernetic modification). We're also beginning to support Wraith, but code support is still much in development.
This is an open-world MUSH, allowing free roleplay between anyone according to their preferences, with an emphasis on a troupe (online tabletop group) approach, so characters of any power level may be created and encountered, and groups of players may choose to participate in either freeform or campaign-style play. See the FAQs or ask on-game for more details.