I worked at Xerox and got a chance to actually see an Alto up close, although it was not in operating condition. When I started in the mid-90s GlobalView, the successor to the OS that ran on the Star (which was a successor of the Alto), had been ported to run on Sun workstations and was still in use inside the company. They also ported it to run on top of Windows but performance was horrible and people only used it if they had to.