Scroll Reveal.js
Declarative on-scroll reveal animations.
Nprogress
For slim progress bars like on YouTube, Medium, etc
Gpu.js
GPU Accelerated JavaScript
Fine Uploader
Multiple file upload plugin with progress-bar, drag-and-drop.
Knockout
Knockout makes it easier to create rich, responsive UIs with JavaScript
Grunt
Grunt: The JavaScript Task Runner
Q
A tool for making and composing asynchronous promises in JavaScript
Typeahead.js
A fast and fully-featured autocomplete library
Lowdb
An extendable JSON database for Node and the browser powered by lodash
Toastr
Simple javascript toast notifications
Nock
HTTP mocking and expectations library
Riotjs
The 1kb client side MV* library
Scroll Magic
The jQuery plugin for magical scroll interactions.
Filament
Filament is a real-time physically based rendering engine for Android, iOS, Windows, Linux, macOS and WASM/WebGL
Browser Sync
Keep multiple browsers & devices in sync when building websites. http://browsersync.io
Raven Js
JavaScript client for Sentry
Marko
Marko template engine