The built-in dev tools have improved drastically in the latest versions of Firefox and that's also why [Firebug.next](https://getfirebug.com/downloads https://g

The built-in dev tools have improved drastically in the latest versions of Firefox and that's also why [Firebug.next](https://getfirebug.com/downloads https://getfirebug.com/downloads) (aka Firebug 3) isn't a standalone panel any more, but is integrated with and built upon the native dev tools.