Zork

Zork /zork/ n.  The second of the great early experiments
   in computer fantasy gaming; see {ADVENT}.  Originally written
   on MIT-DM during 1977-1979, later distributed with BSD UNIX (as a
   patched, sourceless RT-11 FORTRAN binary; see {retrocomputing})
   and commercialized as `The Zork Trilogy' by {Infocom}.  The
   FORTRAN source was later rewritten for portability and released to
   Usenet under the name "Dungeon".  Both FORTRAN "Dungeon" and
   translated C versions are available at many FTP sites.