Support of Mac OS X 10.7.x Lion, Mac OS X 10.8.x Mountain Lion, Windows 7 SP1 32 and 64 bit, Windows 8 32 and 64 bit operating systems.

ENGADGET: Drobo's new 5N is a speedy $600 NAS for when you need files, stat

"The pace of innovation on the Mac is amazing, OS X Mountain Lion comes just a year after the incredibly successful launch of Lion, " said Philip Schiller, Apple's senior vice president of Worldwide Marketing.

ENGADGET: Apple brings Dictation to the Mac, tells Siri to stay in the car

Starting today, customers who purchase a Mac are eligible for a free copy of OS X Mountain Lion when it becomes available.

ENGADGET: Apple announces next-generation MacBook Pro: Retina display, 0.71-inches thin, shipping today for $2,199