EFi-X is the latest commercial product to allow PCs to boot Mac OS X. A company called Psystar made headlines in April when it introduced its "Open Computer" which was built from generic PC parts and also allowed users to boot Mac OS X Leopard. Psystar advertised the computer as an affordable alternative to an official Apple Mac. Psystar would install a modified version of Mac OS X on their computers to allow them to boot into Apple's operating system. Apple has since sued the company citing copyright infringement.

EFi-X takes a different approach by offering a hardware add-on that allows you to install an unmodified Mac OS X onto certain PC configurations. EFi-X is offering it as a tool for enthusiasts, and not necessarily for those looking to save money:

EFI-X is not for everyone. It is not for who wants to save money, at all. It is for enthusiasts that put expandability and extreme performances before anything else in their computing needs. We heard those voices, and we answered.

Only specific hardware configurations are supported, but if your PC fits those specifications, the EFi-X add-on promises headache free installation and upgrades.

Gizmodo reviews the EFi-X device and finds it lives up to its promises.

Well, I used it to turn my gaming PC into a Mac Pro over the weekend, and I'm somewhat amazed to say this, but it works perfectly. I grabbed all the updates straight from Appleincluding 10.5.5 last night, so you don't have to wait for a hacked patch like you would running a typical Hackintoshinstalled a whole bunch of software and have been using it for several days. It runs beautifully, just like a real Mac Pro.

The installation requires you to plug the device straight into the motherboard, and upon boot does slow down the Leopard boot process (up to 2 minutes), but once up and running the experience is described as seamless. The product sells for $155 and is now shipping.