The RAJAX framework (Reverse AJAX)
The use of XmlHTTPRequest without refreshing the browser is one of the more common ways of differentiating an Ajax application from a more traditional approach. But while rest of the world was learning Ajax, some smart developers have figured out to do the next step and created something called " Reverse AJAX ", or as I call it "RAJAX". Traditional client-server applications (not over the web) which used standard TCP/IP and UDP protocols didn't have to worry about Firewalls, NATs and PATs. Such client-server applications had the ability to intiate connections either way (from client to server, or from server to client). HTTP Protocol, which was built over TCP/IP was designed for specifically for web browsing where its always the clients asking for information and servers replying. By moving traditional client-server applications to Web applications, the users did solve a lot of Firewall/NAT/PAT issues, but gave up a lot on usability and speed. AJAX to some ext