This definitely isn't an exhaustive list of options - there are some other good RIA tools out there certainly.

Assuming you're using Java on the backend, ICEFaces is certainly an option, but the jury is still out even in the Java community as to the utility and desirability of JSF in general. Also, it doesn't really provide the client/server programming model I like in an RIA - it still requires you to maintain UI state on the server.

JackBe and Kapow are neither free nor open source (near as I can tell), however both products look like they are pretty powerful. I like Backbase - it feels a bit like Flex to me, and the component library is pretty extensive.

But in terms of RIA for the browser, I like Appcelerator more because of it's elegant web expression language and messaging/event handling system. No similar facilities exist in any other Ajax toolkit I have encountered. Along with support for tight integration a variety of server-side backends, I have yet to see a browser-based RIA framework with similar capabilities to Appcelerator, which is why I like it so much and included it in this list.

Brandon,

Regarding your moible question... Appcelerator runs out-of-box on the iPhone.

JackBe, Backbase and Kapow are gone or what?

Yes, i agree too, it is a very interesting article, but what about ICEFace?

Great article. Choosing Web UI framework technology is a crucial step in any enterprise internet strategy and your analysis gives a great first pass for me, an architect returning to the UI game after serverside-only work. I'm comfortable I can navigate further with the decision points you use.

yeah after working GWT I feel Flex is best of all RIA at this time given two things

1. Data access server not free 2. Flex Builder cost you but not very expensive 3. that plug-in things makes client think twice or thrice or so no all together

But JSP, PHP, JSF & other server side tag language feels like age old technology and feels like not working on them after Flex 3 and so open source initiative by Adobe...

Microsoft and SUN (JavaFX not even clost to 10% to flex) makes big statement but delivery buggy (goes to microsoft) or over engineer product (goes to SUN)

A wonderful and very useful summary! I am on the cusp of jumping into RIA dev since Adobe AIR has caught my attention (a new ripple that you might consider adding to this analysis).

Although it may be beyond the scope of your purpose, I'd also be extremely interested in RIA tools which support mobile devices. Can of worms? You bet. It is also an inevitable tsunami.

Excellent, very informative article - thanks!