MU*'s a shorthand to refer collectively to text-based multi-user virtual worlds known variously as: Multi-User Dungeon (MUD) Multi-User Dimension / Domain (TinyMUD) Multi-User Shared Habitat / Hallucination (MUSH) Multi-User eXperience (TinyMUX) MUD Object-Oriented (MOO) Multi-User Chat Kingdom / Computer Kingdom / Construction Kit (MUCK) Multi User Shared Experience (MUSE) Massive Adventure Roleplay Epic (MARE) Multi-User Game (MUG) The asterisk's often used in computer programming lan… (More on Mu)