Where possible, creating Web applications — including Ajax-based applications — in a RESTful way avoids a large class of bugs. However, a pitfall of REST (REpresentational State Transfer) is sending duplicate data across similar XMLHttpRequests. This tip shows how the moderate use of session cookies can maintain just enough server-side state to significantly reduce client-server traffic, while still allowing fallback to cookie-free operation.
Rialto (Rich Internet Application Toolkit) is ajax-based cross browser javascript widgets library. Because it is technology agnostic it can be encapsulated in JSP, JSF, .Net, Python or PHP graphic components.