Apple has released, as promised, its Mac OS X Leopard operating system, which is the 10.5 version of its successful OS. It appears that most people think that its new feature, Time Machine, is the most useful improvement over 10.4 Tiger.

Some have blasted Apple for asking for quite a lot of personal information in the registration screen, and argued that probably Microsoft couldn’t have gotten away with it. Surprisingly, Apple did, so far.

"Leopard, the sixth major release of Mac OS X, is the best upgrade we’ve ever released," said Steve Jobs, Apple’s CEO, earlier this month. "And everyone gets the ‘Ultimate’ version, packed with all the new innovative features, for just $129."

In addition to the $129 single license, Apple offers a very affordable Mac OS X Leopard Family Pack, which is a license for five users from a single household, which will retail at $199. Apple also announced that Mac OS X Server Leopard will also go on sale on Friday, October 26. It will reportedly be going for $499 for a 10-client edition and $999 for an unlimited client edition.

Mac OS X 10.5 Leopard requires a minimum of 512MB of RAM and is designed to run on any Macintosh computer with an Intel, PowerPC G5 or G4 (867 MHz or faster) processor.

Apple claims its Leopard features more than 300 new features, such as a new desktop which includes the redesigned 3D Dock with Stacks; a backup feature called Time Machine which lets users easily back up all of the data on their Mac, find lost files and even restore all of the software on their Mac; the complete Boot Camp release, which makes it possible to run Windows natively on Intel-based Macs (you need a separate Windows install kit and license, of course); improved Parental Controls, providing automatic identification of unsuitable content before allowing website access, time limits and activity logs that can be accessed from any Mac on a home network, and other parental control features, etc.

Security was also beefed: Leopard records information about any program you download over the Internet and shows that info to you the first time you run it; and Apple added optional authenticity verification which verifies whether a program is unchanged since it was produced by its developer, among other less obvious improvements.

In April, Apple was forced to push back Mac OS X Leopard’s release date from June to October to ensure the timely release of the highly anticipated iPhone.