Unfortunately for old-school Microsoft, the big hit that Microsoft is celebrating is Office apps on the iPad:

It looks like Apple's free iWork suite for iOS just wasn't enough for many iPad users. One week after landing in Apple's App Store, Microsoft's Office for iPad has already seen more than twelve million downloads, the company tweeted from its Office account on Thursday. The Office apps also topped Apple's list of most popular iPad apps soon after their introduction on March 27 and still remain in the top three spots.

But this is good news for new Microsoft CEO Satya Nadella, since Microsoft Office for the iPad was his first major public release. Not all of—hell, probably not most of—those downloads will result in paying Microsoft customers, but the curiosity was certainly there, and the demand for Microsoft Office is still definitely high. Way to not Ballmer this release up, Nadella.