Apple OS X Mountain Lion will launch today. The latest version of Apple's Mac operating system will cost UK users just £13.99. OS X Lion will be available as a download from Apple's App Store. See also: Apple OS X 10.8 Mountain Lion review

OS X Mountain Lion was announced in February 2012, and is the latest stage in a move by Apple to make OS X more akin to the hugely successful iOS operating system for iPad, iPhone and iPod touch mobile devices. It is only the second OS X iteration not to have the prefix 'Mac', following last year's OS X 10.7 Lion release.

Now users of Mac laptops and PCs will be able to upload and synchronise music, photos and other files with Apple's iCloud online storage. They can send SMS messages over the web to other Macs, iPhones and iPads, as OS X Mountain Lion contains iMessage. There's also a Twitter app in OS X Mountain Lion.

Mountain Lion vs Windows 8

Many observers had suggested that last year's Lion release would be the final OS X, and that the ultimate aim for Apple is to have a single unified OS across all its devices. That it hasn't yet attempted this is thrown into sharp relief by Microsoft's impending Windows 8 launch, in which a single interface will unite Windows PCs, laptops, tablets, smartphones and even the Xbox. Microsoft has also adopted an aggressive pricing strategy for Windows 8, although at $39 in the States, it is still twice as expensive as Mountain Lion is over there ($19). See also: Mountain Lion features you may have missed.

Apple's earning call

Apple announced the much anticipated Mountain Lion launch during its third quarter earnings call yesterday. The earnings release was a disappointment, and Apple's shares dropped about 5 percent in after hours trading on Wall Street. Sales of Macs were slightly up, however.

See also: Mountain Lion: What you need to know.

For more on the changes in Windows 8 and how to use them visit Windows 8 Advisor. For detailed advice on installing Windows 8 Release Preview, read our article: How to install Windows 8.