OpenXava

OpenXava is a framework to develop AJAX Java Enterprise/J2EE applications rapidly and easily. Allows you to define applications just with POJOs, JPA and Java 5 annotations. Feature rich and flexible since it's used for years to create business applications with Java.  
 
 
OpenXava 3.1beta1 has all functionality of 3.0.3 but it generates an AJAX application. Just update to OX3.1 and your OX (3.x, 2.x, or 1.x) application will be AJAX without touching a single line of code.  
 
You can download it from:  
http://sourceforge.net/project/showfiles.php?group_id=123187  
 
More info:  
http://openxava.sourceforge.net