There's been plenty of comment on the Internet lately about Unix reaching the big four-oh this year, although it's not quite clear when its birthday really is.

What we do know is that Unix was conceived in the spring of '69 and gestated over the summer months with a team at Bell Labs Computing Science Research Center that included Ken Thompson and Dennis Ritchie.

Not for them the sort of ponderous development schedules coders at Microsoft enjoyed: While Windows Vista took several years to develop from initial idea to finished product, the fathers of Unix worked to a different beat altogether. How's this for a confident approach to developing what may be the most important operating system the world has ever seen: "I allocated a week each to the operating system, the shell, the editor, and the assembler to reproduce itself ..." Thompson explains.

And so, 40 years ago, something came in to existence. "Although it was not until well into 1970 that Brian Kernighan suggested the name 'UNIX,' in a somewhat treacherous pun on 'Multics,''and' the operating system we know today was born," confirms Ritchie.

Forty years on and Unix is still going strong - mainly in the form of AIX, HP-UX and Solaris. Systems running these Unixes still account for 33.1 percent of server spending, according to the most recent IDC Worldwide Quarterly Server Tracker, compared to 37.3 percent for Windows and 13.8 percent for Linux.

Unix's market share has been declining over the past few years as Linux becomes more popular, but we shouldn't forget that Linux is a Unix derivative. You could certainly argue that the popularity of Linux is a testament to the greatness and durability of Unix - a chip off the old block so to speak. If you add Unix and Linux together as part of the same family, instead of seeing them as competitors, then Unix still accounts for more than half of all server spend.

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