New programming frameworks, such as OpenCL, were created, allowing software developers to use graphics cards in their applications. Much of the software in Mac OS X was extensively rewritten for this release in order to fully take advantage of modern Macintosh hardware. An addition of new end-user features was not a primary goal. Unlike previous versions of Mac OS X, the goals with Mac OS X 10.7 were improved performance, greater efficiency and the reduction of its overall memory footprint. The release of Mac OS X 10.7 came nearly two years after the introduction of Mac OS X 10.6, the second longest time span between successive Mac OS X releases. As a result of the low price, initial sales of Mac OS X 10.7 were significantly higher than that of its predecessors. 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. Mac OS X 10.7 was publicly unveiled on June 8, 2009, at the Apple Worldwide Developers Conference. Mac OS X 10.7 is the recent major release of Mac OS X, Apple's desktop and server operating system for Macintosh computers.
