code: def DocbookSlidesHtml(env, target, source=None, *args, **kw):
      
      # Init list of targets/sources
      if not SCons.Util.is_List(target):
          target = [target]
      if not source:
          source = target
          target = ['index.html']
      elif not SCons.Util.is_List(source):
          source = [source]    
  
      # Init XSL stylesheet
      __init_xsl_stylesheet(kw, env, '$DOCBOOK_DEFAULT_XSL_SLIDESHTML', ['slides','html','plain.xsl'])
  
      # Setup builder
      __builder = __select_builder(__lxml_builder, __libxml2_builder, __xsltproc_builder)
  
      # Detect base dir
      base_dir = kw.get('base_dir', '')
      if base_dir:
          __create_output_dir(base_dir)
  
      # Create targets
      result = []
      r = __builder.__call__(env, __ensure_suffix(str(target[0]), '.html'), source[0], **kw)
      env.Depends(r, kw['DOCBOOK_XSL'])
      result.extend(r)
      # Add supporting files for cleanup
      env.Clean(r, [os.path.join(base_dir, 'toc.html')] +
                   glob.glob(os.path.join(base_dir, 'foil*.html')))
  
      return result
docs: A pseudo-Builder, providing a Docbook toolchain for HTML slides output.