I am looking for a good AJAX open source framework as per the requirement of my application. I have gone through some of them like SweetDev RIA, Jason-RPC etc. but still not sure which one is the best. My application is a Struts-EJB application. I heard that there is an opensource framework which is recommended by Sun Microsystems.
As already mentioned. Every library has something different to bring to the plate. You need to look at what it can do and what your requirements are. Best thing is to actually play with example code and see what you like the best.