From Microsoft:

Microsoft Corp. on Monday announced it has reached an agreement to acquire GitHub, the world’s leading software development platform where more than 28 million developers learn, share and collaborate to create the future. Together, the two companies will empower developers to achieve more at every stage of the development lifecycle, accelerate enterprise use of GitHub, and bring Microsoft’s developer tools and services to new audiences.

It seems like a good fit with Microsoft’s embrace of open source these days.