Mac OS X version 10.5 “Leopard” is the sixth major release of Mac OS X, Apple’s desktop and server operating system for Macintosh computers; it is also the successor to Mac OS X v10.4 "Tiger". Leopard was released on 26 October 2007, and is available in two variants: a desktop version suitable for personal computers, and a server version, Mac OS X Server. Apple offers a reduced-cost upgrade to people who purchased new Apple computers after 1 October 2007 that do not already have Mac OS X v10.5 pre-installed or a Leopard upgrade DVD included. Steve Jobs stated at MacWorld 2008 that over 20% of Macs use Leopard as their operating system. Leopard will be superseded by Mac OS X v10.6 "Snow Leopard", which is expected to ship in the latter half of 2009.
Home Page: apple.com/macosx/