Where does Drupal render the content of the  tag?
template_preprocess_html() gets the tags for the &lt;head&gt;, and adds them to the html.tpl.php template file as $head.

The template file looks like this:

..
&lt;head profile="&lt;?php print $grddl_profile; ?&gt;"&gt;
  &lt;?php print $head; ?&gt;
  &lt;title&gt;&lt;?php print $head_title; ?&gt;&lt;/title&gt;
..