Are you perhaps thinking of JQuery UI? The core JQuery lib is still used. And for basic front end dev it really does offer most of the utility you'll look for in other libs.

1. Get and manipulate dom elements. 2. Register simple event handlers 3. Ajax calls that are simple (frankly all other ajax-ish APIs I've ever seen pretty much copy the design and approach of the JQuery one).

Also a pretty big ecosystem of simple highly focused add-ons. You (still) can get a long way with just JQuery