6to5
Turn ES6 code into readable vanilla ES5 with source maps
Qunit
An easy-to-use JavaScript Unit Testing framework.
Fast Check
Property based testing framework for JavaScript (like QuickCheck) written in TypeScript
Jasmine
DOM-less simple JavaScript testing framework
Rulers Guides.js
Creates Photoshop-like guides and rulers interface on a web page
Stencil
A Web Component compiler for building fast, reusable UI components and Progressive Web Apps 💎 Built by the Ionic Framework team
Hashgrid
A little tool that inserts a layout grid in web pages, allows you to hold it in place, and toggle between displaying it in the foreground or background.
Apitizer
API mocking for client JavaScript applications
Hotel
Start apps from your browser and get local domains without editing /etc/hosts http://i.imgur.com/DrLjbIi.gif
Jscritic
Quickly check how well 3rd party script behaves.
Angular Debaser
Just a better way to test AngularJS apps.
Blanket
blanket.js is a simple code coverage library for javascript. Designed to be easy to install and use, for both browser and nodejs.
Headstart
An automated front-end setup
Csscritic
A lightweight framework for regression testing of Cascading Style Sheets
Thrill
Runs tests in many browsers.
Pioneer
Integration Testing
Wire
A light, fast, flexible Javascript IOC container