- There were two visits.
- Xerox held a stake in Apple in exchange for the visit.
- People from SRI and from Xerox were already at Apple.
- To whatever extent Apple "stole" from Xerox, Xerox had already "stolen" from ARC.
- The Apple projects were underway prior to these visits.
- The primary effect (as far as I can tell) was in convincing all the executives at Apple of the value of the GUI.
The key take away from this bit is honestly that employers should work harder to keep talent. Companies need the talent more than the talent needs the company. Over and over, my research into tech history shows that great talent can flourish at any number of companies, and there are far more great business managers, accountants, and marketers than there are extremely good and visionary engineers.
I do not mean to downplay the impact of great executives. They are important. The talented and visionary engineers are just more rare.
That's my takeaway as well. Larry Tesler says as much somewhere.
I'm not sure about the talent thing. The overall vision for the Mac as a shipping product came from Steve Jobs, who was never really an engineer. The original Mac team members have been very clear on this point. The engineers, however talented and visionary, necessarily had smaller scope (which is why they were engineers and not executives).
Some interesting Polaroid screenshot are found in "Busy Being Born" by Andy Hertzfeld [1], showing windows and a pointer interface for the Lisa, probably predating the PARC visit.
Andy Hertzfeld:
> (…) a mouse/windows based user interface. This is obviously the biggest single jump in the entire set of photographs, and the place where I most wish that Bill [Atkinson] had dated them. It's tempting to say that the change was caused by the famous Xerox PARC visit, which took place in mid-December 1979, but Bill thinks that the windows predated that, although he can't say for sure.
[1] https://www.folklore.org/Busy_Being_Born.html