Web-based test suite for finding out which CSS3 features the browser recognizes.
jQuery Bacon!
Bacon is a jQuery plugin that allows you to wrap text around a bezier curve or a line. You can view a demo below with a conveniently placed slice of juicy, delicious bacon below.
Responsive Design Test Bookmarklet
Bookmarklet which automates an idea by Lennart Schoors where the current page is loaded into a bunch of differently sized iframes, so when working on a large monitor, you can see what a design looks like at a bunch of different smaller sizes quickly and all at once.
Aloha Editor
World’s most advanced HTML5 WYSIWYG Editor gives you a total new experience when editing. It’s faster than existing WYSIWYG technologies and offers unprecedented WYSIWYG functionalities.
Foundation
An easy to use, powerful, and flexible framework for building prototypes and production code on any kind of device.