NetHack is a single player dungeon exploration game that runs on a wide variety of computer systems, with a variety of graphical and text interfaces all using the same game engine. Unlike many other Dungeons & Dragons-inspired games, the emphasis in NetHack is on discovering the detail of the dungeon and not simply killing everything in sightin fact, killing everything in sight is a good way to die quickly. Each game presents a different landscapethe random number generator provides an essentially unlimited number of variations of the dungeon and its denizens to be discovered by the player in one of a number of characters: you can pick your race, your role, and your gender.
For a while NetHack was probably the most popular roguelike game, and it still is one of the most complex. The name is misleading since it does not have multiplayer, and is no cyberpunk game. It bears its name because it was hacked over the net. Its predecessor was simply called Hack and was the work of Don Kneller. NetHack is one of only two games regulyrily mentioned on Illiad's webcomic User Friendly. The other one is Quake, more specifically Quake III Arena.
Nethack was actively developed for about sixteen and a half years. The first version, 1.3d, was released in July 1987 by Mike Stephenson, the currently last, 3.4.3, on 2003-12-08. Though an end of development was never officially announced, new versions seem increasingly unlikely.
Originally, Nethack sported the same ASCII graphics as Rogue and Hack. Over time, the PC versions began to use the extended IBM character set and various versions sported various graphics. Currently, the one for Windows uses a tileset based on the Atari ST rogue graphics, not an optimal solution, since they are 16×16 and thus a bit small, even with a 640×480 screen resolution. In 2007, a 32×32 replacement tileset was released.
At some point, Jaakko Peltonen created a fork of NetHack with an isometric interface, which he called Falcon's Eye. After NetHack 3.4.0 was released in 2001, he more or less abandoned the project, which however lives on in Clive Crous' Vulture.
NetHack is a spectacular dungeon crawl that has been in development for more than 15 years. It's the only game in this feature that we can refer to in the present tense, because it is the only game still being actively worked on. It features random dungeons, enough monsters to fill an AD&D menagerie, and enough commands to create a programming language. The only problem? NetHack has no graphics. Instead, it uses ASCII text characters to depict all the game objects.