Unlike previous versions of Mac OS X, the goals of Snow Leopard were improved performance, greater efficiency and the reduction of its overall memory footprint. Addition of new end-user features was not a primary consideration: its name was intended to signify its goal to be a refinement of its predecessor, Mac OS X Leopard. Much of the software in Mac OS X was extensively rewritten for this release in order to take advantage fully of modern Macintosh hardware. New programming frameworks, such as OpenCL, were created, allowing software developers to use graphics cards in their applications. This is also the first Mac OS release since System 7.1.1 that does not support Macs using PowerPC processors, as Apple now intends to focus on its current line of Intel-based products. As support for Rosetta was dropped in Mac OS X Lion, Snow Leopard is the last version of Mac OS X that is able to run PowerPC-only applications.
Snow Leopard was publicly unveiled on June 8 at the 2009 Worldwide Developers Conference. On August 28, 2009, it was released worldwide, and was made available for purchase from Apple's website and its retail stores at the price of US$29 for a single-user license. As a result of the low price, initial sales of Snow Leopard were significantly higher than that of its predecessors. The release of Snow Leopard came nearly two years after the introduction of Mac OS X Leopard, the second longest time span between successive Mac OS X releases (the time span between Tiger and Leopard was the longest).
Snow Leopard was succeeded by Mac OS X Lion (version 10.7) on July 20, 2011. Since then, Apple has continued to sell Snow Leopard from its online store for the benefit of users that require Snow Leopard in order to upgrade to later versions of OS X, which have all been distributed through the Mac App Store introduced in the Mac OS X 10.6.6 update.