<P> Mac OS X 10.5 Leopard was released on October 26, 2007 . It was called by Apple "the largest update of Mac OS X". Leopard supports both PowerPC - and Intel x86 - based Macintosh computers; support for the G3 processor was dropped and the G4 processor required a minimum clock rate of 867 MHz, and at least 512 MB of RAM to be installed . The single DVD works for all supported Macs (including 64 - bit machines). New features include a new look, an updated Finder, Time Machine, Spaces, Boot Camp pre-installed, full support for 64 - bit applications (including graphical applications), new features in Mail and iChat, and a number of new security features . Leopard is an Open Brand UNIX 03 registered product on the Intel platform . It was also the first BSD - based OS to receive UNIX 03 certification . Leopard dropped support for the Classic Environment and all Classic applications, and was the final version of Mac OS X to support the PowerPC architecture . </P> <P> Mac OS X 10.6 Snow Leopard was released on August 28, 2009, the last version to be available on disc . Rather than delivering big changes to the appearance and end user functionality like the previous releases of Mac OS X, the development of Snow Leopard was deliberately focused on "under the hood" changes, increasing the performance, efficiency, and stability of the operating system . For most users, the most noticeable changes are these: the disk space that the operating system frees up after a clean installation compared to Mac OS X 10.5 Leopard, a more responsive Finder rewritten in Cocoa, faster Time Machine backups, more reliable and user friendly disk ejects, a more powerful version of the Preview application, as well as a faster Safari web browser . An update introduced support for the Mac App Store, Apple's digital distribution platform for macOS applications and subsequent macOS upgrades . Snow Leopard only supports machines with Intel CPUs, requires at least 1 GB of RAM, and drops default support for applications built for the PowerPC architecture (Rosetta can be installed as an additional component to retain support for PowerPC - only applications). </P> <P> Mac OS X 10.7 Lion was released on July 20, 2011 . It brought developments made in Apple's iOS, such as an easily navigable display of installed applications (Launchpad) and (a greater use of) multi-touch gestures, to the Mac . This release removed Rosetta, making it incapable of running PowerPC applications . It dropped support for 32 - bit Intel processors and requires 2GB of memory . Changes made to the GUI (Graphical User Interface) include the Launchpad (similar to the home screen of iOS devices), auto - hiding scrollbars that only appear when they are being used, and Mission Control, which unifies Exposé, Spaces, Dashboard, and full - screen applications within a single interface . Apple also made changes to applications: they resume in the same state as they were before they were closed (similar to iOS). Documents auto - save by default . </P> <P> OS X 10.8 Mountain Lion was released on July 25, 2012 . It incorporates some features seen in iOS 5, which include Game Center, support for iMessage in the new Messages messaging application, and Reminders as a to - do list app separate from iCal (which is renamed as Calendar, like the iOS app). It also includes support for storing iWork documents in iCloud . 2GB of memory is required . Notification Center, which makes its debut in Mountain Lion, is a desktop version similar to the one in iOS 5.0 and higher . Application pop - ups are now concentrated on the corner of the screen, and the Center itself is pulled from the right side of the screen . Mountain Lion also includes more Chinese features, including support for Baidu as an option for Safari search engine . Notification Center is added, providing an overview of alerts from applications . Notes is added, as an application separate from Mail, synching with its iOS counterpart through the iCloud service . Messages, an instant messaging software application, replaces iChat . </P>

What is the next operating system after snow leopard