Apple's 35th birthday is fast approaching but 24 March 2011 is also a significant date for one of the company's key products, it is the 10th birthday of Mac OS X.

On 24 March 2001, Apple resellers opened late and Mac users queued to get their hands on Mac OS X. There was also a series of parties around the world to mark its launch.

"Mac OS X is the most important software from Apple since the original Macintosh operating system in 1984 that revolutionised the entire industry," said Apple CEO Steve Jobs at the time. "We can't wait for Mac users around the globe to experience its stability, power and elegance."

It had previously been rumoured that Mac OS X was going to launch on 24 February 2001, Steve Jobs' 46th birthday, though these proved to be premature by exactly one month.

However, pedants might point out that while it is actually the 10th birthday of the desktop-focused version of Mac OS X, Mac OS X Server 1.0 launched in March 1999, it recently celebrated its twelth birthday.

Based on technology developed by NeXT, which was bought by Apple in 1996 (bringing CEO Steve Jobs back into the fold) Mac OS X replaced Mac OS 9 and was the tenth version of the Mac OS, which itself dates back to 1984.

The different versions of Mac OS X were named after big cats - 10.0 was Cheetah, 10.1 Puma, 10.2 Jaguar, 10.3 Panther, 10.4 Tiger, 10.5 Leopard and 10.6, the current version, is Snow Leopard. On the horizon, there is Mac OS X 10.7 Lion, which will be launched at some time over the summer, to look forward to.