OS X Mountain Lion
The software will set users back $19.99 via the App Store. Those who bought the operating system at any point on or after June 11 will be eligible for a free upgrade to the operating system. Apple will also be bundling it in current Mac purchases from this point forward.
The software comes with over 200 improvements, including wide-ranging integration of iOS features, like Twitter, Apple's Game Center, and iMessage. Facebook integration will be coming to the platform in the fall, according to Apple.
AirPlay Mirroring, notes, and reminder apps have also made their way to the platform. A Power Nap feature will ensure Macs stay up-to-date even while asleep, and a new security tool called Gatekeeper will help fend off malware by controlling application installation.
OS X Mountain Lion can be downloaded now from the Mac App Store. The software is 4GB in size.
Click here to read CNET's review of OS X Mountain Lion.