My understanding is that there’s a direct line from MULTICS to Prime to Apollo, in that
Apollo was founded by former Prime folks who took their philosophy with them.
Apollo’s operating system (Aegis, Domain, Domain/OS) had a lot of good and interesting
ideas and was quite influential despite the relatively small number of people who used it.
A lot of what we take for granted today in distributed computing came via Apollo more than
anywhere else, as Apollo users and alumni took what they learned to other systems.
— Chris