Techcrunch reports that Microsoft is continuing its acquisition spree for competitive productivity apps, scooping up calendar company Sunrise for something over $100 million. This follows the recent release of Outlook for iOS (see The best Gmail client is Outlook? Really?), which was the outgrowth of its acquisition of Acompli, an Outlook competitor, a few months ago.

Apparently, Microsoft intends to continue Sunrise as an independent product family (there are iOS, Android, Mac OS X, and web versions), so I expect we’ll see Windows versions in the offing. Supposedly Microsoft plans to integrate Sunrise functionality in other products, as well.

Sunrise had raised $8.2 million from investors that include Balderton Capital, Resolute.vc, NextView Ventures, Lerer Ventures, SV Angel, BoxGroup, 500 Startups, Slow Ventures, and a long list of angels.