jquip : Smaller, Lighter, Faster, more modular jQuery - include only the parts you want! Don't use it, Don't include it.
Mousetrap : A simple library for handling keyboard shortcuts in Javascript.
css3-mediaqueries-js : make CSS3 Media Queries work in all browsers (JavaScript library)
loglevel : Minimal lightweight logging for JavaScript, adding reliable log level methods to wrap any available console.log methods
Anime.js : Anime.js is a fast, multipurpose and lightweight JavaScript animation library with a simple, yet powerful API.
It works with CSS properties, SVG, DOM ...
Sammy is a tiny javascript framework built on top of jQuery, It's RESTful Evented Javascript.