Source : Free On-Line Dictionary of Computing

Emacs Lisp
     
         A dialect of {Lisp} used to implement the higher
        layers of the {Free Software Foundation}'s editor, {GNU}
        {Emacs}.  Sometimes abbreviated to "{elisp}".  An enormous
        number of Emacs Lisp packages have been written including
        modes for editing many programming languages and interfaces to
        many {Unix} programs.