There was a minor controversy in late 1999 and early 2000 regarding whether the commercial MMORPG EverQuest, developed by Verant Interactive, had derived its code from DikuMUD.

He did not specify whether he meant the code itself was derived from DikuMUD, or if it just had a similar feeling.

( Source code in DikuMUD uses the term " mob " to refer to a generic NPC ; DikuMUD was a heavy influence on EverQuest.

However, AberMUD's legacy lives on in the three major codebases it inspired: TinyMUD, LPMud and DikuMUD.

There has been controversy over whether recent versions of Medievia continue to be derivatives of DikuMUD, and what effect this has on the legality of encouraging players to effectively purchase in-game equipment from the proprietors.

Medievia was, at the time of its creation, based on the Merc MUD codebase ( which in turn was based on DikuMUD ).

The following comparison is based on a copy of the DikuMUD license available here, and explains the compatibility of Medievia at present with the DikuMUD license.

# You may under no circumstances make profit on * ANY * part of DikuMUD in any possible way.

The original CircleMUD began as a modified DikuMUD running on a DECstation at Johns Hopkins University in 1991.

The making of DikuMUD was first announced on Usenet by Hans Henrik Staerfeldt March 27, 1990.

The first DikuMUD was in working development as early as October 1990 and officially opened publicly running at on February 3, 1991.

However, the DikuMUD license includes the following requirement: " You may under no circumstances make profit on * ANY * part of DikuMud in any possible way.

After the Diku group requested clarification, Verant issued a sworn statement on March 17, 2000 that EverQuest was not based on DikuMUD source code, and was built from the ground up.

Merc is a MUD engine derived from Copper, which in turn was based on DikuMUD.

ROM ( Rivers of MUD ) is a MUD codebase derived from Merc, which is based on DikuMUD.

EnvyMUD is a MUD codebase written by Michael Chastain, Michael Quan, Mitchell Tse, David Love, and Guilherme Arnold which was created in 1994 as a derivate of the Merc codebase which itself was based on DikuMUD.

The design and concept of EverQuest is heavily indebted to text-based MUDs, in particular DikuMUD, and as such EverQuest is considered a 3D evolution of the text MUD genre like some of the MMOs that preceded it such as Meridian 59 and The Realm Online.

Medievia has the original four DikuMUD classes, each with strengths and weaknesses.

CircleMUD is freely available, with restrictions provided by the CircleMUD license and the DikuMUD license.

An example of a non-LPC MUD with a clearly identifiable mudlib is MUME, a DikuMUD that implements global support code in its language Mudlle.

In response, the DikuMUD team publicly stated that they find no reason whatsoever to believe any of the rumors that EverQuest was derived from DikuMUD code.

Diku and Merc MUDs did not originally support online creation capabilities — DikuMUD was specifically designed to be a better AberMUD, which was notorious for having a hard-coded world .< ref > A number of different packages were created to add online creation capabilities, the first of these was Armageddon for DikuMUD by Dan Brumleve, Nasri Hajj, and Santiago Zorzopulos, which allowed builders to create zones, rooms, exits, objects, and mobiles interactively through a VT100 menu, or command line driven, interface.

In his book Designing Virtual Worlds, Richard Bartle ( co-creator of the original MUD ) mentioned that " several major codebases ( standalone MUD program suites ) were created from the basic DikuMUD original, the main ones being Circle, Silly, and Merc.

In 1990, the release of DikuMUD, which was inspired by AberMUD, led to a virtual explosion of hack and slash MUDs based upon its code.

This is significant since, were Medievia still to be a derivative work of DikuMUD, it would be bound by the terms of the DikuMUD license.

It is a derivative of DikuMUD that was written in 1990 by Katja Nyboe, Tom Madsen, Hans Henrik Staerfeldt, Michael Seifert and Sebastian Hammer.

" Thus, DikuMUD is not open source software as defined by the Open Source Definition ( OSD ), because the OSD's clause 6 requires " No Discrimination Against Fields of Endeavor ", that is, commercial users cannot be excluded.

Bartle further described how DikuMUD went in the opposite direction to TinyMUD and LPMud, by providing a very well organised hard-coded game that ran " out of the box ".

It added to DikuMUD by allowing modification of operating parameters through the MUD itself rather than having to manually edit configuration files, or even the source code itself.

It has been the basis of a vast number of MUDs, including Avatar, BurningMUD, SlothMUD, TorilMUD, Eris, MUME, Imperial DikuMUD, Northern Crossroads and Arctic MUD, as well as a number of offspring MUD engines such as CircleMUD, Merc, and SMAUG.

The gameplay style of the great preponderance of DikuMUDs is hack and slash, which is seen proudly as emblematic of what DikuMUD stands for.

AberMUD's popularity resulted in several inspired works, the most notable of which were TinyMUD, LPMud, and DikuMUD.

The source code for DikuMUD is publicly available at no charge, anyone can run an unmodified or modified DikuMUD without paying any royalties, and modified derivatives of the DikuMUD code can be publicly distributed.

* MudBytes DikuMUD code and derivative downloads

The popular DikuMUD codebase was developed here, and derives its name from the institution's.

# Michael Siefert, an author of DikuMUD, has stated, " I have been shown the MidThieveia code-version 4 I believe it was ( approx.

Afterwards the DikuMUD at was shut down and the game and development moved to.

The last official release of DikuMUD was Diku Alfa in July 1991.

DikuMUD inspired numerous derivative codebases, including CircleMUD, Merc, ROM, SMAUG, and GodWars.

# Hans Henrik Staerfeldt, an author of DikuMUD, has expressed a clear view that Medievia is derived from their work.

If Medievia is derived from DikuMUD, it is legally required to meet these terms.

DikuMUD is a multiplayer text-based role-playing game, which is a type of MUD.