Source : Free On-Line Dictionary of Computing

Portable Common Loops
     
        (PCL) A language which started out as an implementation of
        {CommonLoops} and turned into a portable {CLOS}
        implementation.  Version 1992-08-28.  It runs under {Lucid
        Common LISP} 4.0.1 and {CMU Common LISP} 16e.
     
        {(ftp://parcftp.xerox.com/pcl)}.
     
        (1992-09-02)
     
        [Was it developed by Richard Harris
        ?]