You have probably heard of AJAX, but have you heard of Comet? Yes, they are both household cleaners you might find under your kitchen sink, but that’s only part of the story.
In the web realm, Comet refers to an architecture that enables a server to actually push data to a client without the client explicitly requesting it. Given that web servers were built to be very good at doing exactly the opposite over a stateless protocol, you should be quite intrigued at this point, so head on over to Comet Daily, a fantastic site that includes incredibly informative articles on Comet, to get some insight on what is going to be the next big thing in web programming.
Right now, there is a series running with the theme of Colliding Comets which includes a number of presentations and rebuttals that discuss opposing philosophies on how to most effectively realize Comet. Trust me, you won’t be disappointed. This is good stuff, and it’s full of substance.
If you find Comet interesting, you may want to also take a look at Dojo, an industrial strength JavaScript toolkit for developing web applications, because it includes cometd, a client that can talk to a Comet server if the server implements the Bayeux protocol.
My upcoming book, tentatively titled Developing with Dojo, includes an in depth example of cometd. We hope to have the book available via Rough Cuts very soon, so if you’re interested in using Dojo with Comet, keep an eye out for future posts about its release.
Hype-tastic!
"Comet refers to an architecture that enables a server to actually push data to a client without the client explicitly requesting it."
Why are there warning sirens going off in my head?
@Robert: It may not have been clear from the post above, but the assumption is that the push takes place *after* a client has requested a connection. It's just that once you have established a connection, it (conceptually, at least) stays open. Lots of good stuff at cometdaily.com explains how it all works (with some rigor, I might add.)
@George : hence, the "Opinion" categorization for this post.
Matthew: you might link the first mention of Comet in your post to the Wikipedia article on the subject, which does a much better job of explaining what Comet is than anything else you're linking here.
The comment box ate my link :(. Let’s try again: Comet in Wikipedia
Jacob, stop trying to promote your "work" everywhere.