I have nothing particularly useful to add to the history here, but just wanted to say how much I appreciate hearing about the MIT ITS machines.
Around 1982, I was a 16-year old hacker living in suburban Maryland, running a CP/M BBS. I came across a text file titled something like ‘interesting phone numbers.’ One of those numbers I tried dialing up to was a local DOD TAC, which then led me to connect (over NCP) to MIT-MC. Playing around at the login prompt, I got a message like ‘That user doesn’t exist; would you like an account?’… and of course said yes! I was HNIJ@MIT-MC, if I recall. A little later, RMS sponsored me (without ever meeting or knowing me) as rms.g.hnij@mit-ai. I also used mit-ccc, which was v6 Unix, for my first foray into both Unix and Usenet. Anyway, it’s really fun to read about these machines that I spent so much time with and learned so much from, yet were so abstract in their existence to me. ;-) —John