So I've been looking at AJaX frameworks over the past few weeks (actually a bunch of coworkers have been doing most of the work, but I'm interested). It seems like everybody has recently jumped onto the bandwagon and are now declaring themselves AJaX frameworks/architectures/founders/etc/etc.
No theoretically the cool uis could have been done with traditional html from the server kind of apps, but AJaX makes it easier because you can move stuff around just like a rich windows app. This was a pain in the olden days because you had to have lots of server hits and stuff and the user didn't like waiting for refreshes to complete to see new sections or get new content.
So there are a few up and comers but no one is perfect yet. I've looked at General Interface (now owned by TIBCO), Isomorphic, DreamFactory, BackBase and Bindows. I'll go into more detail in a future post but for now I'll flip when I see a good open source IDE/Component set that talks with xml services and renders well on IE6 and Firefox.