> It solved a real problem, of not wanting to reload all that code every time a user on an old browser, with a slow connection, changed some data.

Why would the browser have to reload the code (JS files) on every page transition, with proper caching headers?

Click on a link on Amazon and take notice of all the kb of data in the head of every document that doesn't get cached.

	▲	layer8 4 days ago \| parent [-]
		But you were talking about code, not data, hence my question. Also, Amazon doesn’t need to be that way (and wasn’t twenty years ago, the motivating period we are talking about).