Here let me buy you a second cup of coffee.
http://www.mackido.com/Interface/ui_history.html<snip>
Jobs was so hot on the concepts of UI, and the living Demos he say, that he, later, negotiated a deal with Xerox. He gave Xerox a large sum of stock in Apple (worth Millions) if he could come back, and bring some programmers -- to inspire them moreon the concepts of GUI. This was like a one-day tour. This was agreed to by Xerox, and so by no stretch of the imagination could this be called "ripping-off".
PARC was a research center -- meant to inspire development. But they did not really develop products (in the commercial sense), they developed ideas. Saying that Apple learning some of the base concepts and then applying them was "ripping-off" is like saying that Air-Bags are ripping off Newton -- because Air Bags work because they adhere to some of the laws of physics first expressed by Sir Isaac. A silly silly argument. Knowledge builds on knowledge. Xerox didn't see Apple as competition, that is why they let them in -- but they charged Apple, since Xerox believed that their research had value.
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The letters do seem to agree that the Macs UI was created at Apple, by Apple and for Apple. And that little if any Xerox work was taken, and the Mac was in a completely different universe. Some broad concepts were in common, but that is about it. Apple furthered those concepts, developed their own, and had totally different implementations.
The differences in UI between the Xerox UI and Apples' Mac were startlingly different.
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