Wow. Impressive dhtml painting application. This AJAX stuff is getting really sophisticated. Well, okay, that isn't actually sophisticated at all compared to a stand alone program like Illustrator, but because this wasn't possible to do on the web a short time ago (without using Flash that is, or a java applet,) it's pretty cool. Notice your drawing is being recorded on the right, and you can press play at any time and it will recreate your drawing over time.

Personally I'm not very interested in making drawing applications, and I don't want to use these techniques at all for creating publicly facing web pages (mostly because I like to always think about supporting small wireless devices where this stuff isn't going to work well.) But for administrative, and other behind the scenes pages, AJAX allows for some serious improvements.

I'm going to work with the dojo toolkit. Here's the general wikipedia page for Ajax:

Ajax, shorthand for Asynchronous JavaScript and XML, is a Web development technique for creating interactive web applications. The intent is to make web pages feel more responsive by exchanging small amounts of data with the server behind the scenes, so that the entire web page does not have to be reloaded each time the user makes a change. This is meant to increase the web page's interactivity, speed, and usability.