Apple maintains tight control on what Mac OS X 10.5 'Leopard' information emerges, with developers legally required to keep any hitherto unannounced features to themselves.

These tight controls are boosting interest in even the tiniest details about the forthcoming OS.

Apple at WWDC released a list of features for its 'near final' OS, claiming over 300 improvements.

These include a new Desktop and Dock with Stacks; an updated Finder featuring Cover Flow' a new way to browse and share files between multiple Macs; file previews using Quick Look; Time Machine; Spaces and enhanced iChat and Mail applications, which easily allow users to communicate even more creatively.

One recent blog item - which has been widely reported though now described as removed - claimed Mail, Spotlight and Safari to be faster and more responsive than curent iterations.

Various details emerging on forum websites (according to WinBeta) claims the Mail application has been completely rebuilt and new tools that let developers apply a new feature that lets users of applications share documents in progress online.

Print services are also claimed to have seen significant improvement, featuring document previews in all print dialogues and easier navigation of print options.

Another claim is that DVD Player can now play Blu-ray and HD DVD discs.

Such rumours seem set to become commonplace as Apple prepares to ship the new OS in October.

"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 at WWDC. “We think current and prospective customers are going to love Leopard, and that it will help make the Mac even more popular”.

Mac OS X 10.5 will cost £89 for a single user licence, or £139 for a five-user licence. Prices include VAT.