ZZT was the first game released by Epic MegaGames (which would later become Epic Games). Developed by Tim Sweeney, the graphics were entirely ASCII-based, which was obsolete even at the time of release, however, ZZT sold enough copies to provide funding for Epic's next game, Jill of the Jungle. Epic would also release a sequel, titled Super ZZT, a year later.
Upon release, the shareware version of ZZT was bundled with one game world, Town of ZZT. The registered version included three additional entries: Caves of ZZT, Dungeons of ZZT, and City of ZZT. In 1997, the game was released as freeware, and downloads of it today usually include all four game worlds.
In addition to being a game, ZZT was also a full game creation system. It included the ability to modify levels and completely reprogram game objects using an integrated scripting language. There is still an active community devoted to building and sharing games using ZZT.