DWR - Ajax and XMLHttpRequest made easy

DWR - Ajax and XMLHttpRequest made easy: "What DWR does for you:
DWR is easy Ajax. XMLHttpRequest without any hassle. It makes it simple to call Java code directly from Javascript. It gets rid of almost all the boiler plate code between the web browser and your Java code.
So you don't need to create servlets and web.xml entries for all your code, you don't need struts config files or JSF magic incantations, no writing Actions or implementing some special interface. Just you, DWR, Java, HTML and Javascript.
DWR gives you a jump-start to being able to create GMail type interactivity. We are gradually moving to a web where more and more is done dynamically, and love it or lothe it that means Javascript. DWR makes the Javascript easier by giving you a set of examples of how to create dynamic sites.
What DWR does not do for you:
It is not a servlet framework. If you are already using Struts, JSF, Webwork or Spring, then DWR fits in just fine. It comes with Spring beans integration allowing you to remote your spring beans to Javascript. "