I don't know the exact numbers, but when I left Microsoft a couple of years ago, the following product divisions were among those based in the 6 buildings of th

I don't know the exact numbers, but when I left Microsoft a couple of years ago, the following product divisions were among those based in the 6 buildings of the Mountain View SVC (https://www.google.com/maps/place/Microsoft+SVC+Building+1/@37.4129045,-122.0787811,16z/data=!4m8!1m2!2m1!1smicrosoft+silicon+valley+campus!3m4!1s0x0:0xc1bc0e6d308e6c78!8m2!3d37.4115677!4d-122.0713422 https://www.google.com/maps/place/Microsoft+SVC+Building+1/@... ): - Outlook.com (formerly Hotmail) - Parts of Office for Mac OS X and iOS - Xbox hardware and accessories (Xbox software was in Redmond) - Windows Phone online services - Microsoft Research Silicon Valley (but that was closed in the first round of layoffs several months after I left) SVC was originally built for Hotmail and WebTV (remember that?). Microsoft also had separate offices in Sunnyvale (in the big cluster of relative skyscrapers just south of Moffett Field), which I believe were mostly folks who came from Skype and/or Nokia.