Well I'd suggest "repo" -- the tool that goes with Gerrit, and collects many git repos into reviewable release units with a manifest. That's what Android does.

(But I'd guess that's probably enough to shoot it down as a tool for Microsoft to ever use, right there. Not rightfully, but likely in fact... maybe that's the old Microsoft though.)

A lot of development around Azure tools is done in the open under various "groups" -- MicrosoftDx, Azure, etc -- there is no one "source repo" for all products. Even when I was at Skype, the repo for that was separate from that for S4B, etc -- I'm sure this has changed in the last few years. But, there isn't a monolithic repo.

Something like Office or Windows, well, that's outside my wheel house of knowledge.

Yup. GVFS: https://blogs.msdn.microsoft.com/visualstudioalm/2017/02/03/...

There is no combined Microsoft codebase