How Microsoft builds software

I got asked a great question by an Imagine Cup finalist who is doing a Software Engineering project at university. He wanted to know all about how Microsoft builds products like Windows, Visual Studio, Office, etc. So, I toddled off to see what was available on the web (mainly as I'm not privy to the specs/building software side of working in a product group - although have a good idea through many friends who do it for a living out here in Redmond) and caught this little gem:

How Microsoft Builds Software from Eli Robillard (thanks Eli!)

Has a big DevDiv (Visual Studio) focus and is a little out of date now I'm sure but is a great start for anyone looking for similar information.