Jelly is an XML based scripting engine. The basic idea is that XML elements can
be bound to a Java Tag which is a Java bean that performs some function.

Jelly is totally extendable via custom actions (in a similar way to JSP custom
tags) as well as cleanly integrating with scripting languages such as Jexl,
Velocity, pnuts, beanshell and via BSF (Bean Scripting Framework) languages
like JavaScript & JPython.

Jelly uses an XMLOutput class which extends SAX ContentHandler to output XML
events. This makes Jelly ideal for XML content generation, SOAP scripting or
dynamic web site generation. A single Jelly tag can produce, consume, filter or
transform XML events. This leads to a powerful XML pipeline engine similar in
some ways to Cocoon.