DomUI, an easy to use Java application and user interface framework built and designed by me has been released as open source today by the company I work for, Itris B.V. DomUI has been in use within Itris for about 2 years now. DomUI has a rich set of components, a metadata discovery layer which helps you by preventing repeated entry of common data ("this field is 5 chars long") and integrates with Hibernate out of the box. It's stateful page handling means that creating rich and complex AJAX UI's is made as easy as possible.
Exceptional in DomUI is that creating new components or page fragments is very easy, done in Java only without Javascript. And there's no XML in sight!!
Please look at the website for more details, a tutorial and a small demo app.