I am beginning to work with the Apache Trinidad API and Facelets. Thus far, I've been using Netbeans 5.5 for my development since there is now a Facelets plugin available for the IDE. The new plug in allows for Facelets projects to be produced in an easy fashion. If you have ever used Netbeans 5.5 and created a JavaServer Faces project, it is very similar.
At first glance, it appears that my favorite thing about Facelets is going to be the templating feature. This technology offers a new way to create templating within a JSF application so that all pages can have a similar layout. I also have read (but not yet tried) about templating within templating...this allows for one to create a header template, for example, and use it within a page layout template. What would that buy you? It allows for one to create various different headers using the header template and apply them to the main layout template. Take a look at this link for more details! So all in all...Facelets looks promising for templating and probably lots more once I get into it.
The Apache Trinidad project is an open-sourced API for web applications...it used to be owned by Oracle and known as ADF faces. The Trinidad project contains some of the most advanced JSF components available, and I think it is great that Oracle has donated the project to Apache. It integrates seamlessly with MyFaces to allow one the ability for easy creation of JSF applications with a great selection of advanced components and page layouts. Please check the wiki for more information. I will blog more about this great project once I've sunk my teeth into it a bit farther. So far, I can tell you that the configuration with Facelets is fairly simple...there are a few steps but it is not too bad. Netbeans 5.5 appears to function great for this application model since you now have the ability to use the new Facelets plugin. If you are interested in using the original Oracle ADF Faces components within a WYSIWYG environment, JDeveloper offers excellent tools. I have not yet attempted to use Trinidad within JDeveloper, but I will do so once I've gotten it to function as expected within Netbeans 5.5.