Stimulus
A modest JavaScript framework for the HTML you already have
Dragula
:ok_hand: Drag and drop so simple it hurts
Zepto
Zepto.js is a minimalist JavaScript library for modern browsers, with a jQuery-compatible API
Jasmine
DOM-less simple JavaScript testing framework
Pdfmake
Client/server side PDF printing in pure JavaScript
Sinon.js
Test spies, stubs and mocks for JavaScript.
Bootstrap Daterangepicker
Date range picker component for Bootstrap
Paper.js
The Swiss Army Knife of Vector Graphics Scripting – Scriptographer ported to JavaScript and the browser, using HTML5 Canvas. Created by @juerglehni & @jonathanpuckey
Marko
Marko template engine
Fuse
Lightweight fuzzy-search, in JavaScript
Pace
Automatically add a progress bar to your site. #hubspot-open-source
Peerjs
Peer-to-peer data in the browser
Apify Js
Apify SDK — The scalable web crawling and scraping library for JavaScript. Enables development of data extraction and web automation jobs (not only) with headless Chrome and Puppeteer.
Node Browserify
browser-side require() the node.js way
JSHint
JSHint is a community-driven tool to detect errors in JavaScript code and enforce your team's coding conventions.
Protractor
E2E test framework for Angular apps
Sigma
An open-source lightweight JavaScript graph drawing library