Ember
Ember.js is a JavaScript framework that does all of the heavy lifting that you'd normally have to do by hand. There are tasks that are common to every web app; Ember.js does those things for you, so you can focus on building killer features and UI.
Babylon.js
Babylon.js: a complete JavaScript framework for building 3D games with HTML 5 and WebGL
Sequelize
An easy-to-use multi SQL dialect ORM for Node.js
Anime
Javascript Animation Engine
Yarn
Fast, reliable, and secure dependency management.
Blueprint
A React-based UI toolkit for the web
Draft Js
A React framework for building text editors.
Pdf.js
PDF Reader in JavaScript
Knex
A query builder for PostgreSQL, MySQL and SQLite3, designed to be flexible, portable, and fun to use.
Foundation
The most advanced responsive front-end framework in the world. Quickly create prototypes and production code for sites and apps that work on any kind of device.
Mocha
A simple, flexible, fun javascript test framework for node.js & the browser. (BDD, TDD, QUnit styles via interfaces)
Modernizr
Modernizr is a JavaScript library that detects HTML5 and CSS3 features in the user’s browser.
Alpine
A rugged, minimal framework for composing JavaScript behavior in your markup.
Gulp
The streaming build system
Aframe
:a: web framework for building virtual reality experiences.
Impress.js
It's a presentation framework based on the power of CSS3 transforms and transitions in modern browsers and inspired by the idea behind prezi.com.
Immutable Js
Immutable persistent data collections for Javascript which increase efficiency and simplicity.