Another timepoint: when I first went to Rochester in 1981, the CS lab there was already using a Xerox product, the Lisa, which had the Xerox mouse/windows GUI on a bitmapped screen and a sophisticated OS with built-in wordprocessing, graphics, native networking and various other 'modern' apps. I am pretty sure this was the first commercially available such computer, several years before the Macintosh, although it was not by any means a desktop machine.
I believe the Xerox Alto was first. I was able to play with one at Xerox, Webster. Not a commercial product.
Xerox did have a commercial Alto-like secretaries workstation product... name momentarily forgotten until I dig a little deeper into the archives.
Lisa was Apple's first attempt. It was very expensive—$10,000—and a flop. But it did provide the foundation for the Macintosh.
By 1982 (I think) Xerox did produce magnificent Lisp machines, Dolphin & Dorado.
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