<nav>
  <h4><?=t('Validators')?></h4>
  <a href='http://validator.w3.org/check/referer'>HTML5</a>
  <a href='http://jigsaw.w3.org/css-validator/check/referer?profile=css3'>CSS3</a>
  <a href='http://jigsaw.w3.org/css-validator/check/referer?profile=css21'>CSS21</a>
  <a href='http://validator.w3.org/unicorn/check?ucn_uri=referer&amp;ucn_task=conformance'>Unicorn</a>
  <a href='http://validator.w3.org/checklink?uri=<?=current_url()?>'>Links</a>
  <a href='http://validator.w3.org/i18n-checker/check?uri=<?=current_url()?>'>i18n</a>
  <!-- <a href='link?'>http-header</a> -->
  <a href='http://csslint.net/'>CSS-lint</a>
  <a href='http://jslint.com/'>JS-lint</a>
</nav>