For Firefox 4, Mozilla worked on an inbuilt inspect feature quite similar to the one found in Chrome, and Opera, and available for Firefox with Firebug, The UI For this features is not very polished, but it does the job well enough. If all you need to do is inspect the source code and CSS styling information for elements on the page. without changing anything, this might be adequate.
To enable this feature:
* Go to the about:config page by entering it in your location bar and agreeing with the waring.
* Enter inspector in the filter area.
* Now double-click on the devtools.inspector.enabled entry.
* Restart Firefox.
Now your will find a new entry “inspect” under the “Web Developer”. sub-menu in the Firefox button.You can also find it in the tools menu if you have the menu enabled. or you can toggle it with [ctrl]+[shift]+[i].
The feature wasn’t completed and is not enabled by default. It works well enough but can be quite buggy, so beware before enabling it.
