I need to be able to send asynchronous messages from a server to an applet. The applet would then display that some activity has happened on the server side. It needs to be pretty reliable, and can't have significant time lag. What is the best way of accomplishing this communication? - I have looked at sockets / RMI and would run into firewall related issues. - I can do polling - setup URLConnection from applet side and send events from servlet side and wait until I get data on the ObjectInputStream? But again the overhead is concern what is the best solution. Performance is a key issue.