Stimulus
A modest JavaScript framework for the HTML you already have
Zepto
Zepto.js is a minimalist JavaScript library for modern browsers, with a jQuery-compatible API
Dom Purify
DOMPurify - a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMPurify works with a secure default, but offers a lot of configurability and hooks. Demo:
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
Peerjs
Peer-to-peer data in the browser
Fuse
Lightweight fuzzy-search, in JavaScript
Pace
Automatically add a progress bar to your site. #hubspot-open-source
Jasmine
DOM-less simple JavaScript testing framework
Marko
Marko template engine
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
Node Browserify
browser-side require() the node.js way
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.
Grunt
Grunt: The JavaScript Task Runner