Apple has unveiled a 'near final version' of Mac OS X Leopard, the sixth major release of its OS.

Scheduled to ship in October, Leopard introduces over 300 new features, including a new Desktop and Dock with Stacks, an intuitive new way to organise files; an updated Finder featuring Cover Flow and a new way to easily browse and share files between multiple Macs; Quick Look, a new way to rapidly preview most files without opening an application; Time Machine, a new way to easily and automatically back-up and restore lost files or a complete Mac; Spaces, a feature to create groups of applications and instantly switch between them; and enhanced iChat and Mail applications.

"Leopard is the best release of Mac OS X to date, surpassing even Tiger, and will further extend Mac OS X's leadership as the most advanced and innovative operating system in the world," said Steve Jobs, Apple's CEO. "We think current and prospective customers are going to love Leopard, and that it will help make the Mac even more popular."

Leopard includes a completely new Dock featuring Stacks, which can help manage a user's desktop clutter caused by browser and email downloads. Users can instantly fan out the contents of a stack to easily see each item.

The Finder has also been completely redesigned, adding Cover Flow as a way to quickly browse and locate files and applications.

Finder's new Sidebar simplifies the organisation of files on a Mac, and adds easy access to shared Macs and PCs on a home network.

Subscribers to .Mac can also use the new ‘Back to my Mac’ feature to browse and access files on their remote Macs over the internet. Another new feature, Quick Look, lets users preview almost any file, and even play media files without opening an application.

The company also offered more information on Time Machine, software which automatically maintains an up-to-date copy of everything on the Mac. Users can search their Time Machine archive using Spotlight to find lost files. The feature will back data up to external connected drives, to a server, or to an AirPort Extreme base station's attached hard drive.

The company also confirmed full native 64-bit support; multi-core optimisation; and Core Animation, "helping developers easily create animated user experiences as amazing as Leopard's Spaces and Time Machine in their own applications," the company said.