Unix is 40 years old. 1969, the summer of love for most, was the summer of not having enough computer resources for AT&T Bell Lab employees Ken Thompson and Dennis Ritchie. After the failure of time-sharing system Multics, the two gentlemen needed a computer and an operating system to run Space Travel, an early computer game. Since there was a now-famous "little-used DEC PDP-7" mini-computer at Bell Labs, they took it over and start programming the game into the computer using paper tape. Of course, to run the game, they also needed a file system, some way of handling computer processes. They used the lessons of Multics to create an operating system that, in time, became Unix.
Today, we often see Unix as an operating system on the way out. I don't see that at all. Yes, specific versions of Unix, such as Sun Solaris aren't doing well, and no one believes that HP's HP-UX or IBM's AIX are going to reclaim the server operating system market from Linux or Windows Server. As for SCO's OpenServer and UnixWare, they're both all but dead, thanks to SCO's focus on fighting with the Linux companies. It's a pity, since both of SCO's Unix operating systems are actually good systems.
So why do I think that Unix is actually alive and well if its best known operating systems are either on the way out or slowly losing ground? Because, over the decades Unix has transformed from one form to several others that are doing quite well.
Linux doesn't have a line of Unix code in it -- sorry SCO, but it's true -- but Unix's concepts, theories and practice live on in Linux. If you can use, administrate or program in any of the Unix family, you can do the same in Linux. I should know: it's how I got into Linux.
My own personal history with Unix started in 1979 with the seventh edition of AT&T Unix and 3BSD (third version of the Berkeley Software Distribution), one of the early Berkley Unix distributions. I liked these operating systems then for the same reason I like their modern descendents today: they work well.
Linux and the BSDs, such as FreeBSD, NetBSD and OpenBSD, aren't the only children of Unix that are doing well. If you're running a Mac, underneath your copy of Snow Leopard lies a Unix heart: the Mach 3.0 kernel and BSD programs. Even your iPhone has Unix ticking away underneath its glossy exterior.
It always make me smile when people talk about how hard Unix is, when the operating systems and devices that they think of as being the easiest to run are based on Unix. What's happened is that some developers, such as those at Apple, have been working non-stop on making attractive interfaces for Unix functionality while others, at Sun, IBM, and the Linux vendors, have focused on adding features and functions.
Looking ahead, I see Unix continuing as far as I can see. We may not call it Unix; we may not think of it at Unix. But if our children ever fly real spacecraft across the solar system, I expect the computers that will make that happen will be running code that can be tracked back to Thompson and Ritchie's game.