With quite 65 million users-consumers, scientists, animators, developers, system administrators, and more-OS X is the most generally used UNIX® desktop operating system. But, if you have never upgraded your Mac or any older version of Mountain Lion you still have the option to purchase the license for Mountain Lion as Apple lets you purchase Lion OS X 10.7, Snow Leopard OS X 10.6, and Mountain Lion (OS X 10.8). There are several Macs from which users can install at no additional charges. The installer size measures approximately 4.05 GB and can easily create a bootable USB installer drive for Mountain Lion. Mountain Lion is available in the format of digital download in the Mac App Store and not available on a disc. Mountain Lion is the latest OS X which is available to purchase and has access to download from the App Store.
