Ask YC: Why hasn't Microsoft acquired Xobni already? 18 years ago
Microsoft doesn't want to acquire Xobni because Xobni already works for Microsoft. If Xobni is independent, microsoft benefits, and Xobni takes all the risk and deals with all the cost. Besides, Xobni is developing in an area (desktop office applications) that microsoft has tidily wrapped up.
Microsoft is interested in acquiring companies in markets they don't have wrapped up-- like the internet. Xobni makes outlook better? Great. Except that it's not about Outlook. It's about Gmail.