OS X Mountain Lion has been released, with the update for Macs hitting the Mac App Store today. A $19.99 download - which covers all your personal Macs registered to the same Apple ID - the refresh brings with it more features borrowed from iOS devices like the iPhone and iPad, including a new Notifications Center, Game Center integration, and baked-in iCloud
There's also Dictation, borrowing the voice recognition system from the iPhone 4S and new iPad, though Apple is yet to add full Siri support. New Twitter and - eventually - Facebook integration has also been implemented, with Share sheets throughout the OS to enable straightforward pushing of content to social networks.
Not all Macs will be compatible with Mountain Lion, however. You'll need one of the systems on Apple's approved list; full details, complete with other preparatory steps, can be found in our guide here.
If you bought a Mac sometime between now and June 11, however, you can get a free upgrade to OS X Mountain Lion. Head over to Apple's Up-to-Date program to register your details and get the new software free.
You can find Mountain Lion in the Mac App Store here.