As our system requirements change over time, we have to carefully consider which operating system versions we can support. With Mac users' support needs in mind, we created a system that allows us to support current operating systems while gradually phasing out older versions.
Major Version Support
We support the current major version of Mac OS X and limited support for the two previous OS X versions. After the support period for an operating system ends, that version of the operating system will become completely unsupported. Support phases may vary based on the popularity or release of new OS X versions. For example, if OS X version 10.8 is current, 10.7 will be fully supported and 10.6 will be supported for a limited time.
Note: We only support the latest free incremental update to a major version of Mac OS X. Be sure to check Software Update regularly to ensure that you are using the most recent update.
We will make announcements before any of our supported operating systems change, including before an operating system enters or leaves its support phase. By providing notification of these support changes, we hope that it will ease the transition from version to version of the Mac operating system.
Article ID: 7400087