Prettier : Prettier is an opinionated code formatter. It enforces a consistent style by parsing your code and re-printing it with its own rules that take the max...
fuelux : Extends Twitter Bootstrap with additional lightweight JavaScript controls. Easy to install, customize, update, and optimize. All functionality covered...
HyperTerm : A terminal built on web technologies : JS / HTML / CSS
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
DOM Monster is a cross-platform, cross-browser bookmarklet that will analyze the DOM & other features of the page you're on, and give you its bill of health.