Want an enterprise AJAX solution and don't mind paying for it? We have Backbase, Bindows, Icefaces, Isomorphic SmartClient, JackBe, Nexaweb, and probably many more that I don't know about or didn't think to include. Want to hedge your bets? Almost all of these vendors offer a stripped-down community edition or a free open source license as an alternative to a fully supported offering with enterprise-level features.
The question is, with so many terrific open source AJAX tools, why spend good money for a so-called enterprise solution? I had some preconceived notions about what the answers would be, but I decided to go out and ask other people about it, both vendors and developers. I'll tell you what they said, and what I think now that I've talked to them.
One vendor executive, Ran Meriaz, president of MB Technologies, which makes Bindows, came back with a flowchart for selection. It boils down to two basic choices: First, do you want pure AJAX? If not, then look at other RIA (rich Internet application) technologies (such as Adobe Flex, Adobe AIR, Curl, and Microsoft Silverlight), since you can get additional capabilities and higher performance if you're willing to use plug-ins.
Now, the crux of his decision tree is the definition of "enterprise." Meriaz supplied some characteristics of an enterprise-strength framework. As you might expect, he specified a complete, extendable components library. I agree: If you're going to pay for an enterprise AJAX solution, it should do every common thing you need out of the box, and it should allow you to meet any special requirements of your own without going outside the framework. Open source solutions tend to focus on one area or another, at the whim of the developers.
Meriaz also asked for handicapped accessibility, in the form of adherence to Section 508. This is a worthy goal, although I'm not convinced that it's an absolute requirement for all enterprise applications.