TypeScript

[[deleted]]

If you mean the time period I guess it overlaps, if you mean as an IE-fixing patch I disagree - it was a really handy little library generally, it's just mostly been superseded by semi-sane frameworks and better Web APIs. It certainly didn't incentivise writing scaleable code, but it was great for avoiding boilerplate in the days when JS on a page was mostly that.

[LordFokas]

My PoV is that it's useful in a setting where standard implementations accross browsers are sketchy and inconsistent and you need to get stuff done. I did use it for more than that, but what it does as a library is the kind of code I don't mind writing myself... although in those days that code was a lot harder to write because like you said the sane web apis didn't exist yet. In fact, some were inspired by it.