Pustefix is a framework that helps you to develop web based applications.
The framework consists of two more or less independent parts:
A machinery to apply recursive XSLT transformations that produces the UI of the web application.
A Java framework that takes input from the UI to change the application data and supplies changes of the application data back to the UI.
Together, the framework acts similar to the Model-View-Controller pattern (as far as this is possible in the context of a web application).