Downloading and Installing OS X Mountain Lion 10.8.3 OS X Mountain Lion (version 10.8) was a major release of macOS that brought many iOS-inspired features to the Mac. While it has since been succeeded by many newer versions, it remains a critical operating system for users with older Mac hardware that cannot support modern software.
Before downloading, ensure your Mac meets these hardware and software specifications: Mac OS X Mountain Lion Installer - Apple Support Mac OSX Mountain Lion 10.8.3 Free Download
The specifically introduced key improvements, including support for Windows 8 in Boot Camp and the ability to redeem iTunes gift cards using the Mac's built-in camera. How to Get OS X Mountain Lion 10.8.3 Downloading and Installing OS X Mountain Lion 10