The cat-and-mouse game between hackers and Apple takes another move, with news that Apple's new Leopard operating system has already been successfully installed on Windows PCs.

[ See related Special Report: Leopard spotting ]

The OSx86 Scene forum has 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 be counter to Apple's terms and conditions.

The forum is offering full instructions on how to install the system, including screenshots of the installation process.

Not all the features of Leopard function with the patch -- Wi-Fi support, for example, is reportedly inoperable. Historically, Apple's likely next move will be to track down and act against those behind the hack.

The move to make Leopard work on a PC is just the latest in Apple's continual struggle with the hacker community.

Also this weekend, a crew of hackers unleased Jailbreak Me, an online service that iPod Touch and iPhone users can navigate to in order to break into these devices in order to install applications on them.

Apple has encountered similar trials each time it releases a new version of its operating system, as PC-using hackers want the OS, but not necessarily the Mac.

Apple as yet hasn't allowed virtualization software developers to create ways in which Mac OS X can be run on an Intel-based Windows machine, though this weekend's Leopard news shows it's possible.