I was looking at the monitors of my colleagues Sumanth and Rajesh on the screens they were working on a project. I felt some difference in the screen and when I saw it close there were all html tags and style sheets that got displayed in the whole page along with the actual page. I asked them what it was. They told me it was a firefox extension that helps web developers look at the html/style sheet source along with the page. This helps in looking at the whole layout of the page and the styles applied to each element simultaneously rather than going to view source and trying to find out where the element is and what style has been applied. And more often the style sheet is referred from a separate file and you may not be able to view the source of it. I downloaded it and tried the extension on gmail and looked at the div layouts. I am sure this is a great extension that will help any web developer working on the presentation layer. Works only in Firefox browser.