CSSToXSLFO is a utility which can convert an XML document, together with a CSS2 style sheet, into an XSLFO document which can then be converted into PDF, PostScript, etc. with an XSLFO-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. The tool has a command-line interface. There are special packages for using it with XEP from RenderX, XSLFormatter from Antenna House and FOP from Apache.