Eclipse RAP team has just released its 1.0.
The RAP project enables developers to build rich, Ajax-enabled Web applications by using the Eclipse development model, plug-ins with the well known Eclipse workbench extenstion points, JFace, and a widget toolkit with SWT API (using qooxdoo for the client-side presentation). The project has graduated from incubation and released its 1.0 release.
In fact, Eclipse RAP and Java2Script have a lot in common. Both are based on SWT API and have goals to provide ways for developers to share the same base of code for products that deploy to the web and the desktop. Here is overview of Eclipse RAP. And you can also read Java2Script’s overview for comparisons.
And you can also check out Eclipse RAP demo to get more details. It’s interesting to see that RAP and Java2Script have 2 very similar demos: RAP’s RWT Control Demo and Java2Script’s SWT Control Examples.
More discussion may be found at ajaxian.com.
Related link: InfoWorld Eclipse offers AJAX server
RAP uses qooxdoo as its widget library.
J2S has no relation with RAP and qooxdoo. J2S is just considered as similar to RAP/Qooxdoo technology
I think J2S is quite different with RAP because J2S converts java to javascript but RAP bridges java to javascript by AJAX and Java code need not be converted to javascript code. In RAP almost every event will be sent from browser to server on which the event will be handled by real java bytecode run on JVM, so you can debug your java code in eclipse both on RAP and RCP.