macOS 10.12 Sierra is now available from the Mac App Store. Anyone who has purchased Mac OS X 10.6 Snow Leopard, OS X 10.7 Lion, OS X 10.8 Mountain Lion, or has OS X 10.9 Mavericks, OS X 10.10 Yosemite, or OS X 10.11 El Capitan installed will be able to upgrade for no cost.
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macOS Sierra is Now Available on the Mac App Store
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macOS Sierra is Now Available on the Mac App Store