Java(TM) Boutique - Using FOP with Java:
"In data-centric applications, you are often required to produce reports and documents in various formats. One of the challenges facing the developer world is to find a generic and consistent way of manipulating a structurally diverse data set to produce formatted reports. For example, if you write a program to accept a certain data set and produce a PDF formatted report, than in order to produce an HTML report on the same data set you might have to write a different program. In this article, we will see a relatively new technology involving W3C standard named XSL-FO. FOP gives us the flexibility to operate on XML structured data, apply an XSL Stylesheet, do the XSLT transformation and publish the data in various formats such as PDF, PCL, SVG, TXT and many other…"

http://javaboutique.internet.com/tutorials/FOP/