Firefox’s alpha build, Firefox Aurora, will make it to their beta channel in March, I believe, but there are some absolutely incredible new features for developers, including a new “free form CSS” section, a 3d modeling view of the website (see below), and much more.

Here’s what the 3d model looks like, where (naturally) the elements extrude from each other, etc.:

More on the 3d view:

This 3D view (which was previously available in an add-on called Tilt), stacks elements as they are nested in the DOM and lets you see elements that are hidden or off the page. You can zoom in and out, rotate and pan the view to see the page from any angle that is helpful to you.

The 3D view is fully integrated with the rest of the Page Inspector functionality. You can open the HTML view or the Style Inspector for more information about the element you’ve clicked on in the 3D view. You can also change selected elements using the breadcrumbs on the toolbar.

The more useful feature is the free-form CSS, which we plan to use in the development of our sites going forward, simply because it’s a smoother interface than the Google Chrome inspector. But even the beta channel has already received a tremendous upgrade already.

Basically, in the free-form CSS editor, you can make textual changes directly to the CSS of the site, and see it update live. That’s a feature included in the Chrome inspector, of course — the difference is that this one truly is free form. You don’t simply add styles for elements you inspect; you can add whatever you like and see it update live on the page. Great stuff!

Unfortunately, there’s one huge thing it’s missing. Why, Mozilla, are the sizes of each div not displayed? This is a standard feature in both Google Chrome and in Firebug, the addon for Firefox which is most popular at the moment for inspecting websites.