The Jargon File (version 4.4.7, 29 Dec 2003):

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.


The Free On-line Dictionary of Computing (30 December 2018):

NetHack

    /net'hak/ (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
   organised by Mike Stephenson.

   Version: NetHack 3.2 (Apr 1996?).

   (http://win.tue.nl/games/roguelike/nethack/).

   FAQ
   (ftp://rtfm.mit.edu/pub/usenet/rec.games.roguelike.nethack/).

   FTP U Penn (ftp://linc.cis.upenn.edu/pub/NH3.1/) No large
   downloads between 9:00 and 18:00 local or the directory will
   be removed.

   Usenet newsgroup: news:rec.games.roguelike.nethack.

   E-mail: .

   (1996-06-13)