AJAX (in case you’ve been living under a rock) is Asynchronous Javascript And XML (but in reality it is really a grab bag of technologies) and is one of the key elements of the whole Web 2.0 thing.
AJAX is usually used to improve the user experience for web applications. Using XHTTPRequest, client-side Javascript can communicate with the server minimizing the number of page refreshes necessary to perform a given task. This is usually coupled with Javascript/DOM scripting that provides richer and/or more intuitive UI elements.
Ruby on Rails leads the AJAX charge with outstanding support out of the box. And given the incredible hype surrounding Ruby on Rails, you could be forgiven for thinking that if you wanted to use AJAX, you’d pretty much have to use R-on-R.
Thankfully for old WebObjects developers like myself, that is not the case.
Using the Metaparadigm JSON-RPC bridge Jean-François Veillette built a framework that provides AJAX support for WebObjects applications and released it into the wild. Anjo Krank wonderized that and included it in ProjectWONDER and Mike Schrag has done some great work extending it by adding additional components.
I built a small application using the Ajax.Framework from ProjectWONDER and demoed it at the last tacow meeting. You can get it here.