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

eXperimental LISP
xlisp

    (xlisp) An experimental programming language
   combining a subset of Common Lisp with an object-oriented
   extension capability (Class and Object types).  It was
   implemented by David Micheal Betz at Apple to allow
   experimentation with object-oriented programming on small
   computers.  The C source code has been ported to Unix,
   Microsoft Windows, Macintosh, Amiga, Atari, and
   MS-DOS.

   Version 2.1 of the interpreter, by Tom Almy is closer to
   Common Lisp.

   (ftp://wasp.eng.ufl.edu/), (ftp://cs.orst.edu/),
   (ftp://glia.biostr.washington.edu/).

   E-mail: Tom Almy .

   Microsoft Windows version
   (ftp://ftp.cica.indiana.edu/util/wxlslib.zip).

   Macintosh version (ftp://netcom.com/pub/bskendig/).

   Usenet newsgroup: news:comp.lang.lisp.x.

   (2000-08-14)