GWT Vs Echo2

Echo2 is another AJAX framework, and it's similar to GWT in how it's used to create the UI. Echo2 has widgets to create the UI component similar to GWT. Though both framworks use similar APIs, they work very differently.

In Echo2 framwork, you compile your java source to java class files and run them on server. When a client-side event is triggered, it must be handled by server. The interface built with Echo2 needs to hit the server more often. The advantage of is that you don't have to deal with an RPC API because RPC happens all by itself. Echo2 doesn't need to send all the JavaScript to the browser at once. It sends only what is needed by the current state of the application.