It also does CSS debugging, after a fashion. It will show you the structure of your webpage, and as you hover over the HTML, it will both show you the stylesheet that controls that particular chunk of the page (including the main and inherited bits) but will highlight it on the page itself. Really, it has to be seen to be believed. What tweaks I’ve done to my new template successfully were all done with that. Before I had this tool, making any effort to debug CSS was a wild crapshoot. I couldn’t always tell what DIV was in control where or what part of the page it controlled. Now that’s trivial. If you do any webpage development at all – including customizing your blog’s template – this is a download you need.