css3

In the March meeting that just happened, Tom did a good job of quickly covering the DOM, explaining that every browser implements the DOM differently, and then telling us that we shouldn't have to worry about that because of libraries like jQuery. jQuery handles all the incompatibilities behind the scenes and gives you a single method to call all the time. It's great for developers - it just works. If you ever do research on plain DOM methods, you'll quickly find pages talking about which browsers support those methods and how to get the same effect in all browsers.