Re: Mighty GEM (or GEOS?)

You'll all be thinking of GEOS rather than GEM, surely? GEM was the one that came with the Atari ST and was also available for all of the other 16-or-better bit machines from Digital Research, GEOS was — I think — the Commodore 64 one with the surprisingly complete set of applications. I've seen other 8 bit GUIs but never anything that went significantly beyond a basic proof of concept, with a calculator, text editor and nothing much else of production use.