The Linux Foundation has released its annual report on the top contributors to Linus Torvalds's open source operating system, and there's a new name on the list: Microsoft. For years, Microsoft kept its distance from the open source movement, and at one point, CEO Steve Ballmer referred to Linux as a cancer, seeing the open source OS as a threat to Microsoft's Windows operating system and other proprietary tools built by the Redmond software giant. But in recent years, the company has come to realize that it needs the open source community on its side.