I'm the chairman of of YesLogic, the company that makes the Prince formatter. Prince is a
fantastic product for creating PDF documents. Most of the documents in
this world should reside on the web and never end up in a PDF file.
However, sometimes you want to fixate information (e.g., for printing
or archiving) and in these cases you want a flexible tool for
generating PDF using web standards. The latest edition of a book I co-authored on CSS is typest using Prince. I'm also the CTO of Opera.
I've authored many of the sample documents and sample applications that are showcased on the Prince site. Also, I'm studying the fascinating world of Wikipedia and have published some notes on how the markup can be improved for printing purposes.