Amiga OS
                      Apple II
                     BeOS
                    Bob
                   Common Desktop Environment
                  GEM
                 GEOS/GeoWorks
                IRIX
               Lisa Office System
              Mac OS
             Magic Cap
            Newton OS
           NewWave  
          NeXTSTEP/OPENSTEP/Rhapsody
         oNLine System/Augment 
        OPEN LOOK
       OS/2
      PenPoint
     Sketchpad
    The X Window System
   TOS
  Windows
 Xerox Star