Iirc when Andy Herzfeld demoed overlapping Windows with automagic clipping Xerox engineers were flabbergasted. Perhaps Xerox had overlapping windows but clipping was left to applications.
In an event, speaking as someone who actually used Xerox's systems years after the Mac shipped, it was hugely inferior in all important respects to the original Mac UI -- any superficial similarities notwithstanding. Again, see Alan Kay's comment.
In an event, speaking as someone who actually used Xerox's systems years after the Mac shipped, it was hugely inferior in all important respects to the original Mac UI -- any superficial similarities notwithstanding. Again, see Alan Kay's comment.