I know how to use javascript and make ajax calls but that's as far as I go. I can find tutorials myself but I can't tell whether the method is good or not so any links will be appreciated.
Thanks
to use ajax push (comet), you must make a server that will keep concurrent connections.
You can really do anything look for echo servers in your favorite language. Java/C/C++.. I'd do this in Java since it can run on Linux as well.
You can use http://www.ape-project.org/ which seems to be done already all for you.. but seems complex.. I'd recommend starting from scratch with a echo server.