XSL-FO and FOP: Mindfire provides Open Source Support

FOP is the Apache hosted Open Source product that can be used to render documents marked up in XML to multiple rendering formats. The output formats include PDF, PCL and text. FOP processes XSL-FO compliant with the W3C recommendation and the PDF output is compliant with PDF Version 1.3 . Other desktop publishing output formats like MIF and RTF are also underway. FOP is the first of its kind which produces commercial quality print output with XSL formatting objects.

http://www.mindfiresolutions.com/FOPServices.htm