Ask HN: Why isn't Plan9 popular?

Hello, I don't have an elaborative question. I 'discovered' Plan9 yesterday. It seems like Plan9 was the successor to Unix. So why don't we see it in the mainstream?

What seemed intriguing to me was that for the last 8 years with all the linux/unix around, I never came across any references in - books/blogs/articles.

link: http://en.wikipedia.org/wiki/Plan_9_from_Bell_Labs

"Plan 9 failed simply because it fell short of being a compelling enough improvement on Unix to displace its ancestor. Compared to Plan 9, Unix creaks and clanks and has obvious rust spots, but it gets the job done well enough to hold its position. There is a lesson here for ambitious system architects: the most dangerous enemy of a better solution is an existing codebase that is just good enough."

- Eric S. Raymond

It's worth noting that Plan 9/Inferno are cited pretty regularly in computer science papers and a number of the ideas of P9 have been absorbed by Linux, such as representing 'everything' with the filesystem. Last I checked, the 2.6.x kernels also support the P9 protocol.

"...for the last 8 years" Yeah, well, Plan 9 hasn't had an official release since 2002.

IMO Plan 9 didn't gain critical mass because Unix is still "good enough". It's also very difficult to keep current with hardware drivers for a niche OS.

However, there are some things that came from Plan 9 that are very much mainstream, the most notable being UTF-8 which was invented by Ken Thompson and first implemented on Plan 9. Linux's clone(2) system call is obviously inspired by Plan 9's rfork.

And one could argue that the Go language is a spin-off of Plan 9 as it's substantially implemented by Plan 9 refugees to Google (Ken Thompson, Rob Pike, Russ Cox) and is explicitly descended from other languages that came out of Bell Labs (Newsqueak, Alef, Limbo). Of course whether Go will be a success is an open question, but I think its chances are as good as any other equivalent language.

There were the problems with the license for some years.

http://www.gnu.org/philosophy/plan-nine.html

Once it became "free" it had too little functionality.

There's too little of the software and it's not so easy to port the existing Unix/Linux software:

http://plan9.bell-labs.com/wiki/plan9/porting_alien_software...

Moreover, very, very little of the hardware is supported.

A lot of Plan 9 innovations have appeared in Linux. One of the outstanding issues are union aka. overlay filesystems, and these are currently being addressed.

That said, Plan 9 seems to see continued use in some niches. For example, Plan 9 has been ported to Blue Gene.

(What's kinda cute is that the Plan 9 kernel (including TCP and such) has fewer lines of code than the Ruby parser, 8000 vs 10000, IIRC.)