Posting some links here as a reference for myself. Been working on setting up Plan9 after having read about it a bunch of times.
Basically a version of unix originally written in the 80s by the creators of UNIX at Bell Labs. It is said to be more in line with the unix philosophy than unix itself.
I wanted to run Plan9 or Inferno-OS (a popular fork, 9front is another popular fork), as either a docker container, VM, or sub-system. As I don't want to boot into it directly and lose access to my normal system.
I ended up finding a project which wasn't to hard to get setup on Ubuntu: https://github.com/9fans/plan9port
Related Links:
https://news.ycombinator.com/item?id=16292162
http://www.9gridchan.org/archive/9grid_FAQ
http://wiki.9gridchan.org/public_grid/index.html
http://fqa.9front.org/fqa8.html
http://www.vitanuova.com/inferno/