hedwards: I forget how exactly that worked out. But Xerox ended up suing over the issue.
Apple was never a licensee, Xerox filed suit during the proceedings where Apple sued MS over the look and feel issue. Xerox ended up suing because if precedent was going to be set for copyright covering look and feel it felt entitled to money from Apple since there wasn't ever a license involved.
Basically, Xerox let the Apple folks in for research purposes. Which is more or less just as stupid as what you were suggesting.
The situation is even more muddled: To quote from Wikipedia:
Xerox was allowed to buy pre-IPO stock from Apple, in exchange for engineer visits and an understanding that Apple would create a GUI product. Much later, in the midst of the Apple v. Microsoft lawsuit in which Apple accused Microsoft of violating its copyright by appropriating the use of the "look and feel" of the Macintosh GUI, Xerox also sued Apple on the same grounds. The lawsuit was dismissed because the presiding judge ruled "that Xerox's complaints were inappropriate for a variety of legal reasons," although it is commonly believed that Xerox simply waited too long to file suit, and the statute of limitations had expired. This was not actually true; the dismissal of Xerox's legal complaint was not based simply on late filings, but rather a lack of legal merit to Xerox's case as it was presented.
^ Pollack, Andrew (1990-03-24). "Most of Xerox's Suit Against Apple Barred". The New York Times. Retrieved 2008-12-01.
Again gotten pretty much from Wikipedia:
Apple actually did license part of its GUI to MS, which when MS expanded the GUI, Apple sued them over because parts of the expansion that were similar to Apple's were not in the original license. In the end, the only thing Apple won in the case against MS was over the trash can GUI. All other items were deemed to be covered by the original license, an obvious expansion or the intuitive way of performing something, or deemed to be copies from elsewhere. Apple's argument of it being a holistic argument failed as the courts decided that the case should be judged on piecemeal basis.
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But getting back to the subject at hand and not a dispute settled long ago in a galaxy ... our galaxy, @OP I think you'd like to get involved with ReactOS as others have pointed out. :)