OS X Mountain Lion, the ninth major release of the world's most advanced operating system, which brings popular apps and features from iPad® to the Mac® and accelerates the pace of OS X innovation. Mountain Lion introduces Messages, Notes, Reminders and Game Center to the Mac, as well as Notification Center, Share Sheets, Twitter integration and AirPlay® Mirroring. Mountain Lion is the first OS X release built with iCloud® in mind for easy setup and integration with apps.