[mst]

Mmm ... while e.g. in React a lot of state libraries are specialised to React, I've had a fair amount of success using e.g. MobX for state management and React as the view rendering layer it was originally advertised at.

But yes, it's not completely binary, hence my saying 'most' a lot - the library/framework distinction definitely has a wide and fuzzy boundary line ala the time years (decades?) of disputes happened because somebody drew a negotiated official border with a really blunt pencil - but I'm advocating the idea that the distinction is a useful way to carve reality at the joints in a sense of "all models are wrong; some models are useful."

Plus, I mean, the 'is it inside' thing would make PSGI/WSGI/Rack/etc. count as a framework since generally they call your application, but they're not really framework-y in spirit on their own (middleware starts to get fuzzier, of course, but I think we're agreed that 'fuzzier' is an inevitably recurring theme here)