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 systems. 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.
ZZT's graphics were obsolete before it was even created; it used the same style of text-mode graphics that Kingdom of Kroz used 4 years earlier. However, ZZT managed to become fairly popular because of its integration of a simple but effective object-oriented scripting language known as ZZT-OOP. At the time this was groundbreaking, as most functionality in prior games had been hard-coded. The language allowed extensibility that no other game was able to provide, and allowed a large degree of community involvement that extended far beyond simply creating level terrain with the built-in editor, but rather involved writing programs to make the game run.
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 ZZT 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. However when the game became obsolete it became freeware, 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.
In the newsletters for the registered version of ZZT, it is apparent that Sweeney initially had not expected the editor to become the most popular feature of his game. Fans' letters to him quickly established this, and Sweeney responded by encouraging registered users to make their own worlds and submit them to him. The best material from these was released in The Best of ZZT.
Basic gameplay of ZZT is very simple. The player is controlled by the 4 cursor keys, and the shift key and a cursor key pressed will shoot a bullet (if the player has ammo). Items that can be picked up include: ammo (each magazine holds 5 rounds), gems (used for currency in most games), torches (used by pressing the T key in darkened rooms, lighting a small area around the player, that moves as the player does), and energizers that give the player temporary invincibility. Enemies include Lions (randomly moving monsters, that may follow the player), Tigers (randomly moving monsters that fire bullets), Ruffians (monsters that chase the player, then rest, then repeat), slimes, and spinning guns.
Third-party worlds for ZZT are diverse, ranging from shoot 'em ups to complex role playing games to a Lemmings clone (Zem). They range from the simple to the complex, from inane to brilliant. An aspects of the game is the culture that has built up within and around it: catch phrases, programming tricks, and even some rather remarkable internet personalities. Information about the community itself can be found at ZUltimate, the ZZT wiki. Many other games have been inspired by ZZT, such as MegaZeux and ZZT's sequel, Super ZZT, the latter being widely criticized for lacking an easily accessible editor function.
Although it has been many years since Tim Sweeney first wrote ZZT, it still has a cult following. ZZT is still for sale through mail order, according to Sweeney in a Gamasutra interview.
Source: Wikipedia, "Zzt", available under the CC-BY-SA License.