Source : Free On-Line Dictionary of Computing

Lisp Object-Oriented Programming System
     
        (LOOPS) An {object-oriented} extension of {Lisp} from the
        {Intelligent Systems Laboratory} at {Xerox} {Palo Alto
        Research Center}.  It is used in the development of
        {knowledge-based system}s.
     
        See also {CommonLoops}.
     
        ["The LOOPS Manual", D.G. Bobrow & M. Stefik, Xerox Corp
        1983].