Animation
Force.js: a JavaScript library that makes it simple to animate HTML elements and navigate around a web page.
lax.js: A small, vanilla JavaScript plugin for creating smooth scrolling animations.
anime.js: JavaScript Animation Engine.
Velocity: Accelerated JavaScript animation.
Bideo.js: a JavaScript library that makes it very easy to add fullscreen background videos to web pages.
Popmotion: JavaScript motion engine. Use for animation, physics and input tracking.
Aos: Animate on scroll library.
ScrollReveal: Declarative on-scroll reveals animations.
Skrollr: Stand-alone parallax scrolling library for mobile and desktop.
Mo.js: Motion graphics library for the web.
simpleParallax: A tiny JavaScript library that adds parallax animation to any image.
Video
Video.js: Universal video embed.
Player.js: A simple HTML5, YouTube and Vimeo player.
jPlayer: HTML5 Audio and Video for jQuery.
Fit Vid.js: A lightweight, easy-to-use jQuery plugin for fluid width video embeds.
Vide: Easy as hell jQuery plugin for video backgrounds.
Flowplayer: The HTML5 video player for the web.
Popcorn Js: The HTML5 Media Framework.
Audio
Loud Links: A lightweight JavaScript library for adding interaction sounds to your website. It does this by creating an HTML5 audio element and using it to play MP3 or OGG audio files.
Howler.js: JavaScript audio library for the modern web.
Tone.js: A Web Audio framework for making interactive music in the browser.
Wavesurfer.js: Navigable waveform built on Web Audio and Canvas.
Sound Manager 2: A JavaScript Sound API supporting MP3, MPEG4, and HTML5 audio.
Amplitudejs: A JavaScript library to design your media controls in your webpage.
Vexflow: A JavaScript library for rendering music notation and guitar tablature.
Sound JS: A JavaScript library for working with Audio.
Games
Pixi.js: Super-fast HTML5 2D rendering engine that uses webGL with canvas feedback.
Phaser: Phaser is a light-weight 2D game framework for making HTML5 games.
Babylon.js: A complete Javascript framework for building 3D games.
Matter.js: A 2D rigid body physics engine for the web.
Egret Core: It a brand new open mobile game and application engine.
Melon JS: A fresh and lightweight JavaScript game engine.
Crafty: It a JavaScript game library.
Engine: Fast and lightweight JavaScript game engine built on WebGL and glTF.
Planck.js: 2D JavaScript Physics Engine.
Forms
Shave.js: A modern JavaScript plugin for truncating text within an html element.
Quill: A cross browser rich text editor with an API.
Cleave.js: Help you format input text content automatically.
jQuery Validation: jQuery Validation Plugin.
Selectize.js: The hybrid of a textbox and <select> box.
Parsley.js: Validate your forms, frontend, without writing a single line of JavaScript.
Fine Uploader: Multiple file upload plugin with process-bar, drag-and-drop.
Pickadate.js: Lightweight jQuery date selector with multi-language support.
Application tools
Choreographer.js: A simple library to take care of complicated animations.
Moveable: A JavaScript library that lets you move, resize, drag, rotate and more.
React: React is a JavaScript library for building user interfaces.
Vue: Intuitive, fast and composable MVVM for building interactive interfaces. No wonder so many companies are offering Vue JS services now.
Next.js: A lightweight framework for static and server-rendered applications.
Angular: It is a development platform for building mobile and desktop web.
CurrencyFormatter.js: A super simple currency formatting library (155 currencies & 7KB gzipped).
Svelte: JavaScript animation engine.
Redux: Predictable state container for JavaScript apps.
Meteor: An ultra-simple, pure JavaScript web framework.
Visualization
Three.js: JavaScript 3D library.
Creepyface: A JavaScript library that makes your face “look” at the cursor, based on position.
Focus Overlay: A library for creating overlays on focused elements.
Swiper: Mobile touch slider and framework with hardware accelerated transitions.
Fabric.js: JavaScript Canvas Library, SVG-to-Canvas (and canvas-to-SVG) Parser.
Aframe: A web framework for building virtual reality experiences.
Html2canvas: Screenshots of JavaScript.
SVGO: SVGO is a Nodejs-based tool optimizing SVG vector graphics files.
Chart.js: JavaScript Animation Engine.
Flowy: A minimal JavaScript library you can use to create flowcharts.
Miscellaneous
Glimmer: A great library that helps with UI components and DOM rendering.
LegraJS: A library that enables you to draw with LEGO-like bricks.
Paged.js: An open-source library for paginating content in the browser.
Flatpickr: Written in vanilla JavaScript, flatpickr is lightweight datetimepicker and calendar solution.
Reveal.js: The HTML presentation Framework.
Leaflet: JavaScript library for mobile-friendly interactive maps.
Uppy: A sleek, modular file uploader that integrates with any website or app.
Impress.js: A presentation framework based on the power of CSS3 transforms.
JS PDF: Generated PDF files in JavaScript.
Intro.js: A better way for new feature introduction for your website project.
Textblock: A JavaScript tool for displaying continuously responsive typography.
MailtoUI: A script that adds a helpful UI component to standard email links.