OS X Mountain Lion is the ninth major release of OS X, Apple
Inc.'s desktop and server operating system for Macintosh computers. OS X
Mountain Lion was released on July 25, 2012 for purchase and download through
Apple's Mac App Store, as part of a switch to releasing OS X versions online
and every year. Named to signify its status as a refinement of the previous OS
X version, Lion, Apple's stated aims in developing Mountain Lion were to allow
users to more easily manage and synchronise content between multiple Apple
devices and to make the operating system more familiar to users of Apple's more
popular mobile operating system, iOS.
The operating system gained the new malware-blocking system
Gatekeeper and integration with Apple's online Game Center and iCloud services,
while the Safari web browser was updated to version 6. As on iOS, Notes and
Reminders became full applications, separate from Mail and Calendar, while the
OS X iChat application was replaced with a version of iOS's Messages. Mountain
Lion also added a version of iOS's Notification Center, which groups updates
from different applications in one place.
Integrated links allowing the user to rapidly transfer
content to Twitter were added to the operating system from launch. Facebook
integration was also planned but unfinished at launch date, and released as a
downloadable update later. OS X Mountain Lion received positive reviews, with
critics praising Notification Center, Messages, and speed improvements over Mac
OS X Lion, while criticizing iCloud for unreliability and Game Center for lack
of games. Mountain Lion sold three million units in the first four days, making
it Apple's most successful Mac OS release to date
