http://en.wikipedia.org/wiki/Xerox_Star#Marketing_and_commercial_reception http://en.wikipedia.org/wiki/Apple_Lisa#Reception The difference is that Xerox was a typical huge bureaucratic corporation with no vision and Apple was a small, nimble company with a vision. So by 1984 Apple released Mac and Xerox never even tried after the Star. A startup company beat the giant behemoth because they understood where things were going and did not QUIT despite huge failures(Apple III and Lisa). By 1982 everything in the land of GUI-based PCs was very uncertain except in the mind of Steve Jobs. Ironically, PARCs failure to follow up on the Star is the opening that Microsoft needed to get into Windows. Had Xerox spun off PARC and that had succeeded, Microsoft would still be a boutique software company.