High Quality Content by WIKIPEDIA articles! Mac OS X Leopard (version 10.5) is the sixth major release of Mac OS X, Apple s desktop and server operating system for Macintosh computers. Leopard was released on 26 October 2007 as the successor of Mac OS X Tiger (version 10.4), and is available in two variants: a desktop version suitable for personal computers, and a server version, Mac OS X Server. Steve Jobs stated at Macworld 2008 that over 20% of Macs use Leopard as their operating system. Leopard was superseded by Mac OS X Snow Leopard (version 10.6). Leopard is the final version of Mac OS X to support the PowerPC architecture as Snow Leopard solely functions on Intel based Macs.