Cocoon is a 100% pure Java publishing framework that relies on new W3C technologies (such as DOM, XML, and XSL) to provide web content.

The Cocoon project aims to change the way web information is created, rendered and served. This new paradigm is based on fact that document content, style and logic are often created by different individuals or working groups. Cocoon aims to a complete separation of the three layers, allowing the three layers to be independently designed, created and managed, reducing management overhead, increasing work reuse and reducing time to market.

blatantly stolen from the Cocoon web page