Microsoft is one of the first--and certainly the largest of--customers of Wolfram Alpha's commercial API (our Wolfram|Alpha API profile). For math and nutritional searches, Microsoft's Bing now uses Wolfram results.
Microsoft continues to built out its cogitative services API portfolio with two more APIs now generally available. The Bing Custom Search API and v7 of the Bing Search API are both GA and ready for production use. The Customer Search API enables targeted searches, and v7 adds filtering.