Google just released the beta version of the Google Web Toolkit (GWT) yesterday. The GWT is Google's response to Microsoft's Atlas. Both of them are AJAX framework.
I have downloaded a copy of it and tried to play with it a little bit. Good thing is I don't need to touch the markup & scripting to write web application. Bad thing is it doesn't come with Mac OS X version of the compiler and runtime binaries (Darn!!!)
Anyway, it is very simular to Echo2 framework. Hopefully, Google's GWT can clean up the big mess in AJAX framework in the opensource community.