I’d strongly recommend the book Dealers of Lightning. Now I should comment that Alan Kay was at Parc and its where he did amazing work that holds up to this day so pay the most attention to his answer of course. But I learned a ton about Parc’s history from Dealers of Lightning.

I’d also point out that Bob Taylor apparently had a hard limit of 50 researchers because he felt that was all he could manage. This meant that he, by this criteria, had to get the absolute best, smartest scientists / researchers he could find. If you look at the sheer number of absolutely brilliant people assembled at Parc during the same time period, it is astonishing: Alan Kay (smalltalk), Butler Lampson (alto, *), Bob Metcalf (ethernet), the founders of Adobe (postscript), Charles Simonyi (bravo which later became Microsoft Word), etc. Close to 100% of modern computing directly came from Parc.