Recently on the Google Labs Aptitude Test there was a question: "What's broken with Unix? How would you fix it?"
What would you have put?
Ken Thompson and I started Plan 9 as an answer to that question. The major things we saw wrong with Unix when we started talking about what would become Plan 9, back around 1985, all stemmed from the appearance of a network. As a stand-alone system, Unix was pretty good. But when you networked Unix machines together, you got a network of stand-alone systems instead of a seamless, integrated networked system. Instead of one big file system, one user community, one secure setup uniting your network of machines, you had a hodgepodge of workarounds to Unix's fundamental design decision that each machine is self-sufficient.
Nothing's really changed today. The workarounds have become smoother and some of the things we can do with networks of Unix machines are pretty impressive, but when ssh is the foundation of your security architecture, you know things aren't working as they should.
Looking at things from a lower altitude:
I didn't use Unix at all, really, from about 1990 until 2002, when I joined Google. (I worked entirely on Plan 9, which I still believe does a pretty good job of solving those fundamental problems.) I was surprised when I came back to Unix how many of even the little things that were annoying in 1990 continue to annoy today. In 1975, when the argument vector had to live in a 512-byte-block, the 6th Edition system would often complain, 'arg list too long'. But today, when machines have gigabytes of memory, I still see that silly message far too often. The argument list is now limited somewhere north of 100K on the Linux machines I use at work, but come on people, dynamic memory allocation is a done deal!
I started keeping a list of these annoyances but it got too long and depressing so I just learned to live with them again. We really are using a 1970s era operating system well past its sell-by date. We get a lot done, and we have fun, but let's face it, the fundamental design of Unix is older than many of the readers of Slashdot, while lots of different, great ideas about computing and networks have been developed in the last 30 years. Using Unix is the computing equivalent of listening only to music by David Cassidy.
http://slashdot.org/story/04/10/18/1153211/rob-pike-responds?nobeta=1