Headroom.js : Headroom.js is a lightweight, high-performance JS widget (with no dependencies!) that allows you to react to the user's scroll.
Vex : Vex is a modern dialog library which is highly configurable, easily stylable, and gets out of the way. You'll love vex because it's tiny (6kb minified...
yepnope.js : A Conditional Loader For Your Polyfills!
darken : Easy control over your dark mode in a web environment
jsPDF : A library to generate PDFs in client-side JavaScript.