Internally Google started on Perforce and gradually replaced its backend. Their client (not available outside their org) is g4 rather than p4.

Some dedicated/stubborn devs also used to (maybe still do?) manage local history in a git-based tool with pushes on demand to a g4 changelist for review.

git5 or something - is this still supported? g4 was awesome (still miss it, now just on perforce...)

I wouldn’t know anymore, but I hope it’s still viable.

Ahh awesome, ok, thanks so much for the lesson. Something to read more about. Cheers.