It had a revenue stream outside of adverting (with pro membership available for a small annual fee), it had clients on every mobile and desk-bound operating system out there, it was hosting pictures for countless blogs.

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Microsoft's Internet Explorer, or IE, has an 85% global share and comes loaded on every PC with Microsoft's Windows operating system.

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Nearly every one is designed to run on Windows, and they can't run on the Mac operating system, unless you install Windows on the Mac.

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