"This article shows you how to publish XML documents in PDF
using Apache Cocoon. Cocoon can create result documents in a
variety of formats, including HTML and PDF. Cocoon's popularity
reflects that of the Adobe's PDF format, which most vendors prefer
for e-mailing richly formatted printable documents and reports.
Cocoon converts not only text content, but also graphs and images.
This article focuses on using Cocoon to dynamically generate HTML
"Although there are alternatives for generating PDF, Cocoon is
preferred because it provides various value-added features..."