Zork

Zork: /zork/ n. The second of the great early experiments in computer
   fantasy gaming; see ADVENT.  Originally written on MIT-DM
   during the late 1970s, 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.