Be prepared to work hard to be a writer. Add citations directly into your paper, Check for unintentional plagiarism and check for writing mistakes. Need to save your citations for later? Redirected from Mac OS X v10. This is the latest accepted revision, reviewed on 24 March 2019. Snow Leopard was publicly unveiled on June 8, 2009 at the Apple Worldwide Developers Conference. Unlike those of previous versions of Mac OS X, the goals of Snow Leopard were improved performance, greater efficiency and the reduction of its overall memory footprint.