If you haven’t tried the Firefox Developer Tools in the last 6 months, you owe it to yourself to take another look. Grab the latest Aurora browser, and start up the tools from the Web Developer menu (a submenu of Tools on some platforms).

The tools have improved a lot lately: black-boxing lets you treat sources as system libraries that won’t distract your debugging flow. Source maps let you debug source generated by transpilers or minimizers. The inspector has paint flashing, a new font panel, and a greatly improved style inspector with tab completion and pseudo-elements. The network monitor helps you debug your network activity. The list goes on, and you can read more about recent developments in our series of Aurora Posts.

After getting to know the tools, start the App Manager. Install the Firefox OS Simulator to see how your app will behave on a device. If you have a Firefox OS device running the latest 1.2 nightlies, you can connect the tools directly to the phone.

Why The Built-in Tools?

The Web owes a lot to Firebug. For a long time, Firebug was the best game in town. It introduced the world to visual highlighting of the DOM, inplace editing of styles, and the console API.

Before the release of Firefox 4 we decided that Firefox needed a set of high-quality built-in tools. Baking them into the browser let us take advantage of the existing Mozilla community and infrastructure, and building in mozilla-central makes a huge difference when working with Gecko and Spidermonkey developers. We had ambitious platform changes planned: The JSD API that Firebug uses to debug Javascript had aged badly, and we wanted to co-evolve the tools alongside a new Spidermonkey Debugger API.

We thought long and hard about including Firebug wholesale and considered several approaches to integrating it. An early prototype of the Inspector even included a significant portion of Firebug. Ultimately, integration proved to be too challenging and would have required rewrites that would have been equivalent to starting over.

How is Firebug Doing?

Firebug isn’t standing still. The Firebug Working Group continues to improve it, as you can see in their latest 1.12 release. Firebug is working hard to move from JSD to the new Debugger API, to reap the performance and stability benefits we added for the Firefox Developer Tools.

After that? Jan Odvarko, the Firebug project leader, had this to say:

Firebug has always been maintained rather as an independent project outside of existing processes and Firefox environment while DevTools is a Mozilla in-house project using standard procedures. Note that the Firebug goal has historically been to complement Firefox features and not compete with them (Firebug is an extension after all) and we want to keep this direction by making Firebug a unique tool.

Everyone wants to figure out the best way for Firebug’s community of users, developers, and extension authors to shape and complement the Firefox Developer Tools. The Firebug team is actively discussing their strategy here, but hasn’t decided how they want to accomplish that.

Follow the Firebug blog and @firebugnews account to get involved.

What’s Next for Firefox Developer Tools?

We have more exciting stuff coming down the pipe. Some of this will be new feature work, including great performance analysis and WebGL tools. Much of it will be responding to feedback, especially from developers giving the tools a first try.

We also want to find out what you can add to the tools. Recently the Ember.js Chrome Extension was ported to Firefox Developer Tools as a Sunday hack, but we know there are more ideas out there. Like most Firefox code you can usually find a way to do what you want, but we’re also working to define and publish a Developer Tools API. We want to help developers build high quality, performant developer tools extensions. We’d love to hear from developers writing extensions for Firebug or Chrome Devtools about how to best go about that.

Otherwise, keep following the Hacks blog to learn more about how the Firefox Developer Tools are evolving. Join in at the dev-developer-tools mailing list, the @FirefoxDevTools Twitter account, or #devtools on irc.mozilla.org.