Phew, Nostalgia indeed. I looked a Plan 9 back in late 90's when we were doing research for alternative OS's and ways of sharing stuff securely across a network without the cruft of DFS...
It had a lot of promise. What did become of it I wonder?
Coraid ships ATA over ethernet storage based on Plan 9.
Bell Labs still uses plan 9 internally and develops it.
9front is a community fork of Plan 9 with a bunch of interesting changes.
There's a small but interested community of die-hard plan 9'ers that care about it, and the principles it set forth. A lot of it came from some very good, very sane development with people who often spend more time thinking than coding (a virtue we could all benefit from I think)
It had a lot of promise. What did become of it I wonder?