The Mozilla team has quietly enhanced the HTML source viewer in Firefox 3.1 so it becomes more easy for web designers to view the source code of all linked elements including CSS files, JavaScript and even web pages.

html source firefox

When you view the HTML code of a web page through View Page Source (or View Selection Source), all the external files used in that web page are now converted into live links as you may notice in the above screenshot.

If you click any of these links, you will directly see the source code of that element. So clicking "abc.html" in the source code view of Firefox 3.1 would open the source code of the web page and not the rendered view.