Ultima Online
It has been proposed by Raph Koster (lead designer of "Ultima Online" and chief creative officer of "EverQuest II") that Diku has resulted in the greatest proliferation of gameworlds due to being the easiest to set up and use. He further pointed out that "Diku codebases did eventually popularize many of the major developments in muds", and that the Diku gameplay provided inspiration for numerous MMORPGs, including "EverQuest", "World of Warcraft" and "Ultima Online".