I would like to introduce these 2 software because I recently realized how powerful they are and can't resist the impulse to recommend them. They really solved a lot of problem for me. The first one I want to introduce is Firebug. If you are a web designer and you have never heard of Firebug, get one now! Cause you have no idea what you have missed. Firebug is an add-on for Firefox ( I think that's how it got its name ). It can track down every detail of your web page, from loading time and sequence to CSS definition of every tiny bit of the page. You can browse the document tree to locate your content and you can also click on the page to find its location in the document tree. At the same time, you can see the detailed CSS definition for that part, you can easily find out how many CSS file have definition for that part, where these CSS files are located and which one is in effective. However, Firebug works only in Firefox (obviously!), but you can not just simply ignore IE users, for they are still the majority of web users. The most frustrating experience in web design is that after you spent a lot of time and finally carved out a good looking design in Firefox and then try it in IE to see how it works but