nethack /net'hak/ n.
[Unix] A dungeon game similar to rogue but more elaborate, distributed in C source over Usenet and very popular at Unix sites and on PC-class machines (nethack is probably the most widely distributed of the freeware dungeon games). The earliest versions, written by Jay Fenlason and later considerably enhanced by Andries Brouwer, were simply called `hack'. The name changed when maintenance was taken over by a group of hackers originally organized by Mike Stephenson. There is now an official site at http://www.nethack.org/. See also moria, rogue, Angband.