In July 1990, I flew from Boston to London for the UKUUG Conference. (I was to give a talk on UNIX standards and specifications.) But there were three talks on the program that blew me away.
They concerned "Plan 9" a new OS being worked on at Bell Labs. It was named Plan 9 from Bell Labs after "Plan 9 from Outer Space," perhaps the worst science fiction movie ever filmed.
Plan 9 is a UNIX clone. But it presents a consistent interface which is easy to use. I am not going to go into it at any length. But, it was the successor to UNIX, which, Rob Pike said, was dead: "It's been dead for so long it doesn't even stink any more." 1
Rob delivered the keynote address at the UKUUG: "Plan 9 from Bell Labs." He's now at Google.
Dave Presotto then spoke about "Multiprocessor Streams for Plan 9." He's at Google, too.
Tom Duff talked about "Rc -- A Shell for Plan 9 and UNIX Systems." Tom's now at Pixar, the proud owner of parts of several Oscars.
Fifteen years later, what had been the UNIX group (1127) has been dispersed. In addition to Rob, Dave and Tom,
Ken Thompson retired to California;
Brian Kernighan is a Professor at Princeton;
Phil Winterbottom is CTO at Entrisphere;
Gerard Holzmann is at NASA/JPL Laboratory for Reliable Software;
Bob Flandrena is at Morgan Stanley;
Sean Dorward is at Google;
Dennis Ritchie and Howard Trickey remain at Lucent/BTL.
But, before it disappeared, the "1127 group" made yet another contribution to OS development: Inferno.
Inferno is a compact OS designed for building "cross-platform distributed systems." It can run on top of an existing OS, or as a stand-alone. The nomenclature owes much to Dave Presotto, who founded it firmly in Dante. The company marketing Inferno is Vita Nuova; the communications protocol is Styx; applications are written in type-safe Limbo, which has C-like syntax.
The 4th edition of Inferno was released in 2005 as free software, but under a mixture of licenses.
1In the July 2005 issue of IEEE Spectrum, there's an article "The End of AT&T" with the blurb:
Once the world's largest company, Ma Bell will soon vanish. But its innovations -- from the transistor to communications satellites to laser cooling-live on. By Michael Riordan
Note what's important. CS isn't.