ZZT

ZZT is an action-adventure video game released by Tim Sweeney under Potomac Computer Systems (later Epic MegaGames) on January 15th, 1991. It received multiple official updates, the final one being ZZT 3.2, as well as a sequel - Super ZZT.

ZZT was originally distributed in a shareware model, with the first game world in the official series, Town of ZZT, being available without charge, and additional game worlds (Caves of ZZT, Dungeons of ZZT, City of ZZT) purchasable via mail order. On October 10th, 1997, the full version of ZZT was made available at no cost. On March 15th, 2020, the release of the Reconstruction of ZZT effectively made the ZZT game engine available under the terms of the MIT license.