[xiaq]

Answering the second question: you won't want to use it in production, but if you have ever been intrigued by one of those Unix philosophy preaches, you should definitely take a look at it. It takes the tool philosophy (build simple tools that are easy to combine) and filesystem metaphor much further, besides addressing some (albeit not all) long-standing Unix WTFs.

Plan 9 is not the most elegant design of OSes, but its simple ways of combing primitives are pretty amazing. Simplicity is underappreciated nowadays.

[smorrow]

"you won't want to use it in production"

Would you mind saying why? It isn't unstable or anything, just unfamiliar, in that you can't write C programs on it. But people do use it in production.

[xiaq]

Well, it's always safer to use widely used solutions in production. That way you encounter fewer bugs, and it's much easier to find a workaround in case you do encounter one.

[stonogo]

this smells like "I don't have a technical reason"

[4ad]

It's slow and doesn't run any software people usually want to run in production. If your "production" needs are something Plan 9 is actually tailored to, sure, go ahead.

I run it as my primary development environment, but what I do is pretty specific, 99.9% people need something else out of their development systems.