They are all ripoff artists
I think you meant 1982 when VisiOn was demoed and not 1992.
[link|http://www.geocities.com/SiliconValley/Office/7101/|In 1981 Xerox had its PARC labs design a GUI to be used in its Altos/Star systems]. Apple was working on a GUI on a modified "Apple II" system before Windows, [link|http://members.fortunecity.com/pcmuseum/vision.htm|VisiOn], or the Macintosh/Lisa came out, but it was very primative. But Xerox had its GUI before Apple, and before that in the 1960's many college students wrote papers on the GUI. More info [link|http://www-2.cs.cmu.edu/~amulet/papers/uihistory.tr.html|A brief history of human computer interaction technology]
it is all one big mess. Don't forget GEM, GeOS, the early Amiga Workbench, and many others. AmigaDOS may have come out in 1985, but the developers of the Amiga had a GUI long before that but couldn't find a buyer. [link|http://area51.upsu.plym.ac.uk/~moosie/amiga/ahistory.htm|They started it in 1982] got a [link|http://amiga.emugaming.com/lorraine.html|prototype in 1983 named Lorraine] and turned it into the Amiga 1000 in 1985 after Commodore bought them out.
Hey, when did Deskmate come out from Tandy? Wasn't it like a primative GUI?
[link|http://pla-netx.com/linebackn/guis/|The graphical user interface galley] shows as many GUIs as are documented in existance.
"Before Christmas it is 'Ho ho ho', after Christmas it is 'Owe owe owe'" - Santa Norm