IBM's developerWorks has published XForms in Firefox, an introductory tutorial about writing XForm:
XForms makes development of Web-deployed applications faster and easier. XForms' clean architecture makes applications more robust, more scalable, faster, and more secure. Except for one little detail, developing with XForms would be a no-brainer. That detail is that no current browsers actually support XForms out of the box. Needless to say, this severely limits what you can do with XForms and where you can deploy them.
However, there are workarounds. Browser plug-ins exist for both Windows® Internet Explorer® and Firefox that add XForms support to these market-leading browsers. XForms processors have also been written in Flash that can be deployed to any browser with a Flash runtime. Finally, there are server-side solutions that precompile all XForms markup to classic Hypertext Markup Language (HTML) and JavaScript programs.
These solutions all have something to recommend them, but for first learning XForms the simplicity of support right in the browser really helps. You can write a piece of a form and then preview it. Then you can change it a little bit more and preview it again. If the form doesn't look quite right, tweak it a bit and reload. Server-side solutions like Chiba are good for deployment, but for learning nothing beats the rapid development cycle of a browser. Therefore, in this article I focus on using the Mozilla XForms plug-in in Firefox.
Speaking of the Mozilla XForms plug-in, they have now released version 0.7.0.1. This release is compatible with Firefox 2.0 and SeaMonkey 1.1 for the first time.