Need help converting HTML documents to PDF? This reference guide shows by example how to use XSLT templates to convert 45 commonly used HTML elements to formatting objects (from the XSL-FO vocabulary) for easy transformation to PDF using XSLT.
CSSToXSLFO is a utility which can convert an XML document, together with a CSS2 style sheet, into an XSL-FO document, which can then be converted into PDF, PostScript, etc. with an XSL-FO-processor. It has special support for the XHTML vocabulary, because that is the most obvious language it would be used for. The tool has a number of page-related extensions. It also comes with an API in the form of an XML filter.