Sixth Edition is from 1975. Let's consider its contemporary large-scale multiuser OS environments:<p>* PLATO at UIUC. Much more sophisticated graphics and extensive support for multiuser gaming, but requires custom (and expensive) terminals. Homegrown mainframe, then CDC hardware.<p>* Michigan Terminal System at University of Michigan and elsewhere. Runs on IBM mainframes.<p>* Multics, ITS, TOPS-10, and who knows what else at MIT. (<i>Not</i> Unix.) Mostly DEC hardware.<p>* Stanford's WAITS, a descendant of ITS. DEC hardware.<p>* Last but definitely not least, DTSS at Dartmouth, running on GE/Honeywell systems.<p>Of these, DTSS is by far the most widely used. Every Dartmouth undergraduate student is required to, at some point, write and debug a BASIC program. Terminals are everywhere on campus and almost everyone uses them for work (homework, research, and homegrown applications for registration and asset management for employees) and fun (games, email). Dartmouth's later BlitzMail is a natural extension of this mindset once things are decentralized to micros.<p>PLATO is widely available at UIUC but it is not proactively forced upon all students like DTSS. Based on <i>The Friendly Orange Glow</i>, some classes require its use but otherwise most seem to discover it from some unused terminal in the basement. No use by university employees.<p>From what little I know of MTS I think this is somewhere in between DTSS and PLATO in terms of adoption, at least at Michigan. Possibly more widespread/proactive at some other installations?<p>Stanford and MIT's systems are not for the masses, in the sense that students at large are not expected to use them. I don't think we're yet at the point where, for several years, anyone (affiliated with the university or not) can go to an MIT terminal (or connect remotely) and get an account. If not, you probably need to know someone in Course 6 or works at LCS. I think Stanford requires SAIL affiliation.<p>If Walter Bright reads this, he can tell us what Caltech is like.<p>Most other universities have computers by this time, of course, but almost always just batch-card systems.<p>Note that Unix is <i>not</i> listed above. I don't believe any university has students using it. Over the next decade there will be an explosion in multiuser, mostly driven by DEC hardware and, at first, DEC software, with Unix slowly, then suddenly, taking market share from DEC's own OSs despite outrage from DEC staff. DTSS, as widely used as it is, remains stuck in BASIC; in 1984 Dartmouth moves heavily into micros by becoming an early Macintosh adopter. PLATO remains isolated at UIUC; the ambitious CDC attempt to commercialize it almost kills the company, and anyway never goes beyond "drill and practice"-type software that wastes the graphical and social features. As mentioned, MIT is <i>not</i> a place where most students get exposure to computers, or otherwise an early pioneer in Unix. This suddenly changes in 1983 with Project Athena; within a few years MIT produces X and Kerberos.