jsFiddle is the perfect solution; it provides a custom environment (based on user selections) to test (or fiddle with) your JavaScript, HTML, and CSS code right inside your browser. A quick tour ...

fontBomb is a bookmarklet that uses html5, javascript, and CSS to allow you to plant bombs anywhere on a webpage. Ever found yourself annoyed by an article, review, or comment? Next time ...

It's called Dash, and it lets users learn how to use HTML, Javascript, and CSS by working through four projects of increasing difficulty. As you progress through the projects — starting by ...