Ajax

When it first came out, a lot of people thought it was just repackaged DHTML that was updated to use newer technologues like CSS, XML, and SOAP. But the methods behind the AJAX techniques for integrating the various technologies on the client side are a lot mote mature and robust.

It works at its fullest capacity if the Client is running MS Windows and the app can use the XMLHttpRequest object. Most people work around that and get cross-os functionality by using iFrames for the server requests instead of XMLHttpRequest - at least until all browsers support XMLHttpRequest on all platforms.

iFrames of course have their own SEO penalties as well as making it almost imposible to bookmark a particular state of an AJAX application. It's also hard to write an AJAX app that doesn't get hosed up when the user hits the "back" button. If they have JavaScript disabled, you're SOOL.

It can give an extremely rich client experience which is the big thing that'll push it foward. When you code for it though, you need to have a good understanding of how the server side will interact with the client side - when/where/why/how.
 
I don't think vb-asp is particularly suited for it. You can use it, but it seems to require a lot of kludgy work-arounds - but that may just be my limitations showing up. JavaScript-asp would probably be better. PHP's not too bad, better than vb-asp. Most of the AJAX work I've seen has used JAVA and/or JSP's for the server-side programming. Fits like a glove in that environment. I haven't heard of anyone doing anything in Perl but have heard that Python/Ruby are good serverside languages for it.
EDIT: There's also a good sized ASP.NET community playing with it.


Edited by dpyers - 23 December 2005 at 8:27pm

ajax is nice, gmail and google maps are good examples of ajax in particular applications.  ajax used wrong can kill your server, I seen an ajax application out there that keeps a connection open by re-connecting every 30 seconds, that will limit your apps ability to scale.  Use ajax wisely.  Maestro's suggestions are good, small segments of the site can definately have ajax support, just make sure your javascript has failback logic in case xmlhttprequest object isnt available.