Although flexible web layouts are designed to work with most current browsers, Mozilla Firefox and the Firebug extension are recommended for developing new layouts and widgets. Together they provide strong support for developing web applications.
The Firebug extension includes features for inspecting the HTML, DOM, JavaScript, and CSS on the pages. It also includes a JavaScript debugger and many other features.
You can get the Mozilla Firefox browser at www.mozilla.com and the Firebug extension at www.getfirebug.com.
Some of the following examples write information to the Firebug console. If you prefer to use a different browser for development, you can modify the code to use another method of output.