|You may also be interested in the Holometabolous project which builds on Cocoon. From the Holometabolous website:
Holometabolous is a customizable web portal accessible from any device that can connect to the Internet. Built upon world reknowned opensource software, with a comfortable BSD liscence Holometabolous is an integrated, best of breed, standards compliment Java/XML/SQL publishing system available free of charge, with source code. Personalization, user tracking, and use of web applications such as bulletin boards, link collections, chat, advertising and more are enabled by simply inserting tags. Extensibility is easily acheived with Java, and customzation(sic) through XML.
The development of a publishing framework like Cocoon facilitates the creation of powerful websites using custom tags, databases, different style sheets and down right beautiful seperation of every aspect of the programming, logic and display of a site.
A framework of this sort cuts down a lot of time/money that would have to be spent custom developing or buying the same thing. After getting the infrastructure (buying, downloading, developing, etc.) in place the next step is to make the applications that will drive the website.
While there are some unique, or at least less common web based applications most sites use some combination of a common set. Getting these applications developed and to connect to a database, to work together, maintain state, etc. can be a repetitive process that sucks time/money unnecessarily.
Just as Cocoon is the engineering platform which puts valuable theories and concepts into use, so a collection of powerful application modules could extend Cocoon to the highly functional level most people interested in an application server need one for.