Apache Cocoon is a web development framework built around the
concepts of separation of concerns and component-based web development.

Cocoon implements these concepts around the notion of 'component
pipelines', each component on the pipeline specializing on a
particular operation. This makes it possible to use a Lego(tm)-like
approach in building web solutions, hooking together components
into pipelines without any required programming.

Cocoon is "web glue for your web application development needs".
It is a glue that keeps concerns separate and allows parallel
evolution of all aspects of a web application, improving development
pace and reducing the chance of conflicts.

WWW: http://cocoon.apache.org/
