Screenlog.js
Bring console.log on the screen
Brjs
BladeRunnerJS (BRJS) is an open source development toolkit and framework for modular construction of large single-page HTML5 apps. It consists of a set of conventions, supporting tools and micro-libraries that make it easy to develop, test, deploy and maintain complex JavaScript apps.
Vorlonjs
A new, open source, extensible, platform-agnostic tool for remotely debugging and testing your JavaScript. Powered by node.js and socket.io
Roughdraft.js
Quickly create an interactive HTML mock-up by auto sourcing lorem ipsum/images generators, with minimal html markup, and no server side code
Stacktrace.js
Framework-agnostic, micro-library for getting stack traces in all web browsers
Jasmine Ajax
jasmine-ajax - A library for faking Ajax responses in your Jasmine suite.
Argon
An open-standards augmented reality platform for the web
Yeoman
Yeoman - a set of tools for automating development workflow
Apitizer
API mocking for client JavaScript applications
Framer
Modern Prototyping Tool
Headstart
An automated front-end setup
Gremlins.js
Monkey testing library for web apps and Node.js
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.
Sinon.js
Test spies, stubs and mocks for JavaScript.
Csscritic
A lightweight framework for regression testing of Cascading Style Sheets
Punch
A fun and easy way to build modern websites
Grunt
Grunt: The JavaScript Task Runner