1) MUD server 
DikuMUD is a multiplayer text-based role-playing game, which is a type of MUD. It was written in 1990 and 1991 by Sebastian Hammer, Tom Madsen, Katja Nyboe, Michael Seifert, and Hans Henrik Stærfeldt at DIKU (``Datalogisk Institut Københavns Universitet``)—the department of computer science at the University of Copenhagen in Copenhagen, De...