Apple has sold two million copies of Leopard, the latest version of its Mac OS X operating system, since its release on Friday. The company said the Leopard sales rush outpaced that of its predecessor Tiger, until now the most successful Apple operating system.

The two million sales figure includes copies of Leopard sold at Apple retail stores, Apple authorised resellers, the online Apple Store, under maintenance agreements and those copies bundled with newly shipping Macs.

Leopard, which is priced at $129 in the US, is the sixth major release of Mac OS X. It has over 300 new features, including visual improvements, refinements to the Finder search tool, a 'Time Machine' automated backup system and greater user-friendliness overall. But observers have been quick to point out flaws in the OS, including a Windows-like 'Blue Screen of Death' experienced by some users while installing the software as well as its apparent incompatibility with the latest version of the Java programming language.

Meanwhile, resourceful online hackers have already figured out how to successfully install Leopard on Windows-based PCs. Users on the 'OSx86 Scene' forum have released details of how Windows users can migrate to Apple's new OS, without investing in new hardware - even though installing Leopard on a PC may run contrary to Apple's terms and conditions.

The process is not a straightforward one: simply placing a Leopard retail DVD into a PC will not work, since it contains a file format that's readable only on Macs. It is instead necessary to get hold of an ISO image of Leopard, apply a patch to get that image to install, and then fool the PC into loading the whole thing from a USB drive.

This is the latest chapter in Apple's ongoing struggle with hackers. The launch of the company's much-touted iPhone has been followed by ongoing efforts to prevent hackers 'unlocking' the device to allow it to work on mobile networks other than Apple's exclusive US partner AT&T.

© 2007 ENN