Apple does sell Snow Leopard from its online store -- the price is $19.99 -- but as a interim step for customers running even older editions who can, and want to, upgrade to something newer, such as Lion or Mountain Lion. Snow Leopard is offered by Apple because it's the oldest edition that provides access to the Mac App Store, the sole distribution outlet for all later OS X upgrades, including Lion, Mountain Lion and Mavericks, which are available only as downloads.
Also part of Tuesday's update for Safari 7 were several non-security improvements and enhancements, including a new preference setting that lets users turn off website notifications and a fix for a glitch where the browser loaded a page or generated search results before the user pressed the return key.
Safari 7.0.3 and 6.1.3 can be obtained by selecting "Software Update..." from the Apple menu, or by opening the Mac App Store application and clicking the Update icon at the top right.
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