It’s official! This week Apple finally announced what I predicted. Mac OS 10.5, nicknamed “Leopard”, will be released at 6:00 PM ET on Friday, October 26th. The fifth major revision since OS X came on the scene in March of 2001, Leopard follows in the pawprints of “Cheetah”, “Puma”, “Jaguar”, “Panther” and “Tiger”. It appears to be the biggest, most aggressive of the “big cat” Mac OS X upgrades, sporting over 300 new features. We’ll get into specifics about Leopard’s exciting new capabilities in the coming weeks.

Will you need a new Mac to run Leopard? Hardly. Apple lists minimum system requirements as any Intel-based Mac, any PowerPC G5-based Mac, and PowerPC G4 Macs with 867 MHz or faster processors. PowerPC G3 processors didn’t make the cut, but the 867MHz G4 machines go back to 2001. Think Windows Vista will run on a six-year-old PC? Hardly.

You’ll need a Mac with a DVD drive, as the Leopard installer comes on a DVD. You’ll also need 9 GB of hard drive space (that should no problem) for a full installation, and although Apple says Leopard will run in 512 MB of RAM, I would get more. 1 GB would be better. 2 GB would be mighty fine.

What if you just bought a new Mac? Do you have to buy Leopard? That depends. Apple has announced the “Leopard Up-to-Date Program”, where, if you purchase a Mac between October 1st and December 29th that doesn’t come loaded with Leopard, you can buy Leopard for $10 (basically the cost of shipping you the DVD).

If you’re relatively new to the Mac and this is your first major “upgrade”, here’s some things to remember and look forward to. Unlike Windows (especially Vista), there is no caste system in Mac OS X upgrades. There’s no crippled Home edition, no overpriced “Ultimate” edition. There’s just Mac OS X. One operating system to rule them all (sorry, J.R.R.). With it you get the head, the tail, the whole darn cat (sorry, Mr. Quint).

Your Mac OS 10.5 “Leopard” DVD contains a standalone installer. In other words, unlike Vista upgrades, you don’t need Mac OS 10.4 “Tiger” already installed on your Mac to get the Leopard installer to work. You could, in fact, wipe your drive clean (after backing up your stuff, of course) and install Leopard for a “tidy cat” fresh start. We’ll talk more about getting your system ready for Leopard next time.