This reminds me of the excellent episode of Changelog in which Facebook's head of open source discussed the logistics of managing React so that the public version is exactly the same as the version used by Facebook itself: https://changelog.com/211/
Really drove home the concept that open-source requires significant thinking and discipline when a library becomes heavily used.
I've been told directly by multiple Angular team members that over 70% of Google apps uses Angular in some fashion.
They have said the usage of Angular off of HEAD of master publicly in the past as well, but I don't recall off the top of my head where they have said this.
Well, this thread definitely shined some new light on the area for my. I was actually under the impression that Angular (at least 1.*) wasn't really used within Google. I guess I'm just that stupid and naive.
Yeah I think that's the key difference: the size of the production apps. Though to be fair, Angular is a much bigger part of the front-end stack than React and not something that would be feasible to retrofit GMail/YouTube/etc. with.
Really drove home the concept that open-source requires significant thinking and discipline when a library becomes heavily used.