A subset of us still use plan9, usually in the form of 9front.
Every time I think of Plan9, I get a little misty eyed and wistful. I'm just old enough to remembering time sharing systems and mainframes. These days looking at whats called cloud, I'm seeing a lot of the old architecture coming back, loosely speaking. Mobile devices are like the new dumb terminals, the browser is the shell, and the cloud is our mainframe. If you want to extend the analogy further we even pay for time in a convenient monthly subscription, whether that be Netflix's cloud or your favorite remote music service.
Circling back to plan9, it really was the ideal system, and for the way things are going these days, it's really only a matter of time before we see the return of Plan9 or something built in effigy of it. I say this with a straight face, from the filesystem to the network model, from top to bottom Plan9 was a new paradigm that extended on the original Unix system in ways we still haven't replicated today in a mainstream environment the way it was then. The way the network layer and system layer intertwined to form an actual everythings-a-file system was bonkers the first time I tried it, coming from the Linux world where this claim is often made and isn't always true.
Now that the 9 system is back in the community's hands it's just going to take one group to be the next Inferno, similar to redhat, and put on the suits and ask for money and youll see the rest of the industry start to join in. It might just be my tainted opinion as a Gopher, but we're letting good stuff go to waste, we should be evolving this technology while the creators are still around to give input about their vision.
Glenda will ride again, I just hope I'm alive to see it.