Even more sophisticated was Dartmouth Time Sharing System <https://en.wikipedia.org/wiki/Dartmouth_Time_Sharing_System>. Unbelievable capabilities and userbase for 1988, let alone 1968!
[1]https://en.wikipedia.org/wiki/Berkeley_Timesharing_System
[2]https://en.wikipedia.org/wiki/Compatible_Time-Sharing_System
[3]https://en.wikipedia.org/wiki/Livermore_Time_Sharing_System
[4]https://en.wikipedia.org/wiki/Time-sharing#Notable_time-shar...