XSieve is an XML transformation language based on combination of XSLT (an XML transformation language) and Scheme (a Lisp dialect). XSieve is a powerful tool for complex data transformation tasks.
An implementation of DSSSL, a style language to format SGML or XML documents.
OpenJade contains backends for various formats (RTF, HTML, TeX, MIF, SGML2SGML, and FOT). This project also maintains OpenSP.