In the early days of the Web, all you needed to know to craft web sites was HTML. More than a decade later, the situation has changed. Modern web sites are a product of several distinct technologies, and web developers must be proficient in all of themHTML, CSS, JavaScript, and the DOM, among others.

Then a couple of years ago, AJAX came along and every web development tool on the market became obsolete overnight. Today you can no longer rely strictly on tools that were designed for the creation of static pages. This is where Firebug comes in.

Firebug, an extension I wrote for the Firefox browser (www.mozilla.com), makes web development fun again. Combined with your favorite text editor, the freely available Firebug (www.joehewitt.com/software/firebug/) is a highly productive IDE for the complete stack of AJAX technologies.

Firebug Overview

Firebug's biggest draw is its convenience. As you browse with Firefox, you can open Firebug at any time to begin working on any page. Firebug appears either as a separate window or as a small panel at the bottom of your browser. Tabbed browsing and Firebug are best friends; each tab can hold a separate Firebug session, which always reflects the current page as you browse.

Firebug breaks the page down into a set of tabs that depict its most important aspectsHTML, CSS, JavaScript, the DOM, network activity, and a console for errors and log messages. No tab is an island; Firebug lets you browse code just as you browse the Web by presenting objects as hyperlinks that can take you from one view to another.