Day.js is a minimalist JavaScript library that parses, validates, manipulates, and displays dates and times for modern browsers with a largely Moment.js-compatible API. If you use Moment.js, you already know how to use Day.js.

Anime.js is a lightweight JavaScript animation library with a simple, yet powerful API. It works with CSS properties, SVG, DOM attributes and JavaScript Objects.

HTML Reference.io is a free guide to HTML. It features all elements and attributes.