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

Adventure Definition Language

    (ADL) An adventure game language
   interpreter designed by Ross Cunniff  and
   Tim Brengle in 1987.  ADL is semi-object-oriented with
   Lisp-like syntax and is a superset of DDL.  It is
   available for Unix, MS-DOS, Amiga and Acorn
   Archimedes.

   (ftp://ftp.uu.net/usenet/comp.sources.games/volume2),
   (ftp://ftp.wustl.edu/systems/amiga/fish/fish/f0/ff091).

   (1995-03-20)