Look inside the head element with Professor X
Whereas X-Ray lets you view the HTML code used inside the current document’s
body element without viewing source, Professor X reveals the contents of the document’s
head element. A neat way of taking a look at metadata, scripts, and css files. I like how the extension turns URLs specified in certain elements to live links. Makes checking people’s CSS files really easy ;-).
Suggestion for improvement: Professor X would be even more useful if CSS
By the way I noticed that the X-Ray extension now works in the latest version of Firefox (18.104.22.168 at the time of writing). Great!