I'd like to elaborate further, and in concrete terms, a blog post from late last year on Talking to C-Level Execs about XForms. This will also make more sense of the XForms is a killer app of Web 2.0 messaging you got from me in this post.

For a long time now, web applications have had to use middle tier coding to backfill for the underpowered client tier and its inability to talk directly to server tier applications like DB2 that provide the persistent storage for the web. The Web 2.0 movement generally is about defining web applications that factor out the middle tier, allowing users of client applications to create and collaborate on content that Web 2.0 server applications natively understand how to store and serve.

Applications like XForms and DB2's PureXML form an instance of this movement. The server tier (DB2) moves itself closer to consumability by the Web 2.0 client tier by providing the ability to expose web services that give direct access to database table operations. Meanwhile, the conceptual client tier (XForms) now contains a comprehensive interactivity layer to drive a rich front-end user experience as well as a communications layer that allows the client to speak directly to web services. The net result is that a large class of important applications are enabled without the need for middle tier programmers.

To learn more about this union of technologies, including reference customer information, have a look at the new Tax Solution Education Kit.