Here is a very cool article on Microsoft’s Open Source Lab.
Microsoft�s Open Source Software Lab is an ambitious research project. Located on the company�s main campus, the lab houses more than 300 servers, which collectively run more than 15 versions of UNIX and 50 Linux distributions. It boasts a team of senior-level programmers and system administrators, some of whom were architects of popular Linux distributions or authors of well-regarded books. In short, the lab is one of a few such facilities in the world dedicated to open source research.