Check Out the Source Code For the Xerox Alto
jfruh writes The Xerox Alto is a computer legend: it was never sold to the public, but its window-based OS was the inspiration for both the original Mac operating system and Windows. Now you can check out its source code, along with code for CP/M, a similarly old school (though not graphical) operating system.
it wasn't woz.
it was bill atkinson.
http://www.folklore.org/StoryView.py?project=Macintosh&story=I_Still_Remember_Regions.txt&topic=QuickDraw