In early 1989 there were three instances of AberMUD running in the UK, the Southampton one, one at Leeds University and a third at the IBM PC User Group in London, ran by Ian Smith. In January 1989 Michael Lawrie sent a licenced copy of AberMUD3 to Vijay Subramaniam and Bill Wisner, both American Essex MIST players. Bill Wisner subsequently spread AberMUD around the world.
AberMUD3 was extended to create AberMUD4, most notable by Rich Salz.
In 1991, Alan Cox wrote AberMUD IV (unrelated to AberMUD 4) and then AberMUD V, which was also used, with graphical extensions in the Elvira game by Horror Soft, a trading name of Adventure Soft. AberMUD V was later released under the GNU GPL.
AberMUD4 was improved by Alf Salte (Alf), and G.Sorseth (Nicknack) to create Dirt. Their May 1993 final release of Dirt 3.1.2 is used by most of the remaining AberMUD games on the internet.