The MUD trees below depict hierarchies of derivation among MUD codebases. Solid lines between boxes indicate code relationships, while dotted lines indicate conceptual relationships. Dotted boxes indicate that the codebase is outside the family depicted.
Note that codebases are different from individual servers, in the same way that a biological family/genus/species is different from a specific bird at a zoo or fossil imprint in a museum. Some of the codebases below are incredibly popular, with many servers based off them; other codebases may only be found on archive sites, making them available but effectively extinct. For a list of specific servers using some of these codebases, see the Chronology of MUDs article.
^Lawrie, Michael (2003). "Escape from the Dungeon". "I had also taken over a new game called AberMUD that two of my wizards, Anarchy (Alan Cox) and Moog (Richard Acott) had originally written at Aberyswyth University and Alan was now converting to Unix at Southampton University. Alan ended up taking a year out so I took on AberMUD and roped in a couple of programmers in to help keep the thing maintained and expanded. [...] In 1991, I sent a copy of AberMUD to Vijay Subramaniam and Bill Wisner (our only two American MIST wizards) and as far as MUDs being generally available to the world, the rest is history which oddly isn't true for the credits in AberMUD since a huge amount of the original authors were removed somewhere."
^Aspnes, James. "MUD Info". Retrieved 1991-04-19. "TinyMUD 1.0 was initially designed as a portable, stripped-down version of Monster (this was back in the days when TinyMUD was designed to be up and running in a week of coding and last for a month before everybody got bored of it.) The basic idea was to include the minimal object-creation and locking features of Monster without throwing in all the hairy stuff. Since then a lot of the hairy stuff has been reinvented. It might be interesting to go back and look at the Monster docs and see how much of its functionality eventually showed up in TinyMUD."
^Bartle, Richard (2003). Designing Virtual Worlds. New Riders. p. 741. ISBN0-13-101816-7. "TinyMUD was deliberately intended to be distanced from the prevailing hack-and-slay AberMUD style, and the "D" in its name was said to stand for "Dimension" (or, occasionally, "Domain") rather than "Dungeon;" this is the ultimate cause of the MUD/MU* distinction that was to arise some years later."
^ abcBartle, Richard (2003). Designing Virtual Worlds. New Riders. p. 9. ISBN0-13-101816-7. "AberMUD spread across university computer science departments like a virus. Identical copies (or incarnations) appeared on thousands of Unix machines. It went through four versions in rapid succession, spawning several imitators. The three most important of these were TinyMUD, LPMUD and DikuMUD."
^ abBartle, Richard (2003). Designing Virtual Worlds. New Riders. p. 11. ISBN0-13-101816-7. "One player, Stephen White, decided in 1990 to extend the functionality of TinyMUD and write TinyMUCK (muck being a kind of mud). Using this as his template, he then produced MOO (MUD, Object Oriented)."
^ abBartle, Richard (2003). Designing Virtual Worlds. New Riders. p. 11. ISBN0-13-101816-7. "MOO had two important offspring: Pavel Curtis' LambdaMOO (which was to become a favorite of journalists, academics, and social misfits) and, via CoolMUD, ColdMUD (an attempt to create a software-engineering quality virtual world authoring system)."
^Mulligan, Jessica; Patrovsky, Bridgette (2003). Developing Online Games: An Insider's Guide. New Riders. pp. 452–453. ISBN1-59273-000-0. "1990 [...] Shattered World, the first Australian LPMud, opens. "This MUD is the source of a private-distribution LPMud server used by a handful of spin-off MUDs in the US."—George Reese"
^Shah, Rawn; Romine, James (1995). Playing MUDs on the Internet. John Wiley & Sons, Inc. pp. 164–165. ISBN0-471-11633-5. "DGD, created by Dworkin aka Felix Croes, is a complete rewrite of the LPmud game."
^ abTowers, J. Tarin; Badertscher, Ken; Cunningham, Wayne; Buskirk, Laura (1996). Yahoo! Wild Web Rides. IDG Books Worldwide Inc. p. 141. ISBN0-7645-7003-X. "MudOS and Amylaar:: There are a couple versions of LPmuds that you might run into. More are being developed as coders and wizards improve their games. Both MudOS and Amylaar are descendants of LPmuds, and Amylaar is an especially popular version."
^"The History of Pike". Pike. Retrieved 2009-09-09. "In the beginning, there was Adventure. Then a bunch of people decided to make multi-player adventure games. One of those people was Lars Pensjö at the Chalmers university in Gothenburg, Sweden. For his game he needed a simple, memory-efficient language, and thus LPC (Lars Pensjö C) was born. About a year later Fredrik Hübinette started playing one of these games and found that the language was the most easy-to-use language he had ever encountered."
^Shah, Rawn; Romine, James (1995). Playing MUDs on the Internet. John Wiley & Sons, Inc. p. 22. ISBN0-471-11633-5. "DikuMud first appeared in mid-March of 1990 when a group of programmers at the Department of Computer Science at the University of Copenhagen, Denmark got together and began work on a multiplayer game that is similar to but improved on AberMuds. These coders were Hans Henrik Staerfeld, Katja Nyboe, Tom Madsen, Michael Seifert, and Sebastian Hammer."
^ abcdeBartle, Richard (2003). Designing Virtual Worlds. New Riders. p. 10. ISBN0-13-101816-7. "...several major codebases (standalone MUD program suites) were created from the basic DikuMUD original, the main ones being Circle, Silly, and Merc. Merc spawned ROM (Rivers of MUD) and Envy, among others, and these in turn had their own spinoffs."
^Cowan, Andrew (2001-09-17). "MUD FAQ Part 4". Internet FAQ Archives. "SMAUG: [...] History: The SMAUG code started out as a Merc2.1 MUD called "Realms of Despair" in 1994. It wasn't until 1996 that it was given its name, and the first public release wasn't until December of 1996. The interest in the code spread like wildfire, and within a few months and a few revisions there had been over 20,000 downloads of the distribution."