I worked on the xerox product OS (Pilot) written by my manager, and was on the team with the designers of Multics and Swift, MIT's OSes. At MIT we all ran 4.15

I worked on the xerox product OS (Pilot) written by my manager, and was on the team with the designers of Multics and Swift, MIT's OSes. At MIT we all ran 4.15bsd and then 4.2bsd and UNIX was so far ahead we focused on improving it, mostly. Pilot, Multics, CTSS, were nowhere near as powerful or developer friendly as UNIX. UNIX killed off OS research for a long time!