Plan 9 is an operating system designed by Bell Labs. It’s the OS they wrote after Unix, with the benefit of hindsight. It is the most interesting operating system that you’ve never heard of, and, in my opinion, the best operating system design to date. Even if you haven’t heard of Plan 9, the designers of whatever OS you do use have heard of it, and have incorporated some of its ideas into your OS.
Plan 9 is a research operating system, and exists to answer questions about ideas in OS design. As such, the Plan 9 experience is in essence an exploration of the interesting ideas it puts forth. Most of the ideas are small. Many of them found a foothold in the broader ecosystem — UTF-8, goroutines, /proc, containers, union filesystems, these all have their roots in Plan 9 — but many of its ideas, even the good ones, remain unexplored outside of Plan 9. As a consequence, Plan 9 exists at the center of a fervor of research achievements which forms a unique and profoundly interesting operating system.
I’ve never used Plan 9, but whenever I read about I feel like it makes sense, like that’s how things are supposed to be. I’m sure its approaches present their own unique challenges, problems, and idiosyncrasies, but the idealised reality in articles like these make me want to jump in.
It is very interesting to study plan 9 as a way we could evolve unix past it’s early roots. I really like plan9 building on unix strengths in the network space, which is good. But it also highlights how our industry gets held back by legacy dominance. It’s not enough to build something worthy of migrating to, we need some way to overcome momentum, which is where most projects fail.
Sometimes I think plan9 would have been a more progressive platform to embrace than linux. Part of me wishes Torvalds had been more innovative with linux instead of just having linux be a unix clone. However at the same time I’m aware that the main reason linux became popular was because it was a free unix clone. If Linus had tried to improve linux in the same ways that plan9 did, then linux would likely have lost the *nix wars.