Source : Free On-Line Dictionary of Computing

Interlisp
     
        A dialect of Lisp developed in 1967 by Bolt, Beranek and
        Newman (Cambridge, MA) as a descendant of {BBN-Lisp}.  It
        emphasises user interfaces.  It is currently supported by
        {Xerox PARC}.
     
        Interlisp was once one of two main branches of LISP (the other
        being {MACLISP}).  In 1981 {Common LISP} was begun in an
        effort to combine the best features of both.  Interlisp
        includes a Lisp programming environment.  It is {dynamically
        scoped}.  NLAMBDA functions do not evaluate their arguments.
        Any function could be called with optional arguments.
     
        See also {CLISP}, {Interlisp-10}, {Interlisp-D}.
     
        ["Interlisp Programming Manual", W. Teitelman, TR, Xerox Rec
        Ctr 1975].