ZZT

ZZT is an ANSI character-based computer game, created in 1991 by Tim Sweeney of Epic Games (then Epic Megagames), who later designed Unreal. It remains a popular DOS game creation system. ZZT itself is not an acronym for anything; its title was simply chosen so it would always appear at the very bottom of newsgroup listings. However, it was later jokingly mentioned by Sweeney as being short for Zoo of Zero Tolerance, which has mistakenly become a popular belief.

Originally ZZT was shareware, with only one of the four level-sets or "worlds" released without payment. The level released with the shareware copy is called "Town of ZZT". The shareware versions also included "Demo of ZZT", which displayed the basic features of ZZT worlds, and "Tour of ZZT", which allowed the player to view select rooms (some playable) of the four worlds. Three different versions of shareware ZZT were released, with three corresponding registered versions. With about 30,000 registrations worldwide, ZZT was successful enough to finance the production of Jill of the Jungle, a game seen as Epic Megagames' answer to Apogee classics such as Duke Nukem. As the game became obsolete it became freeware, however, with all four worlds of the registered version released for free. The worlds are: "Town of ZZT", "Caves of ZZT", "Dungeons of ZZT", and "City of ZZT"; they can best be described as adventure games.