Mountain Lion will also come with a new edition of Apple's Safari browser, version 5.2, that will a single address bar-search field similar to Google Chrome's, an offline reading list tool, and "iCloud Tabs," which synchronizes open tabs in the browser across multiple devices, including the iPad, iPhone and other Macs.

Safari 5.2 will also support the "Do Not Track" privacy option that lets users signal to websites and online advertisers that they don't want their movements on the Web monitored.

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Also on Monday, Apple confirmed that it will again provide free upgrades to Mountain Lion to customers who buy a new Mac with Lion pre-installed. That program, called "Up-To-Date" by Apple, goes into effect today and continues as long as either Apple or its authorized resellers sell Lion-powered machines.

The free upgrades will be available when Mountain Lion reaches the Mac App Store next month. More information about the program, and an online submission form for a free copy of Mountain Lion, will be posted on at that time.