code: def __build_libxml2(target, source, env):
      
      xsl_style = env.subst('$DOCBOOK_XSL')
      styledoc = libxml2.parseFile(xsl_style)
      style = libxslt.parseStylesheetDoc(styledoc)
      doc = libxml2.readFile(str(source[0]),None,libxml2.XML_PARSE_NOENT)
      # Support for additional parameters
      parampass = {}
      if parampass:
          result = style.applyStylesheet(doc, parampass)
      else:
          result = style.applyStylesheet(doc, None)
      style.saveResultToFilename(str(target[0]), result, 0)
      style.freeStylesheet()
      doc.freeDoc()
      result.freeDoc()
  
      return None
docs: General XSLT builder (HTML/FO), using the libxml2 module.