Nice addition to firebug Rated 5 out of 5 stars
I think is a nice addition to firebug and quite useful. It gives you detailed list of the HTML tags, attributes and CSS that are being used by the element you are inspecting, including browser support. It comes very handy when you don't remember what worked in what browser or if you need to refresh your memory about an unusual tag or CSS rule. Including links to get further information about a particular element, attribute or style is welcomed too together with the search feature.
I think it complements firebug nicely.