You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <alltransclusions gatcontinue="archiver|69" />
  </query-continue>
  <query>
    <pages>
      <page pageid="65" ns="0" title="アーカイバー" />
      <page pageid="67" ns="0" title="tar.gzを展開する" />
      <page pageid="68" ns="0" title="tar.gzに圧縮する" />
      <page pageid="115" ns="0" title="Apache" />
      <page pageid="116" ns="0" title="Apache 2.4をインストールする" />
      <page pageid="118" ns="0" title="Accept Filter" />
      <page pageid="120" ns="0" title="accf dns" />
      <page pageid="129" ns="0" title="Apache 2.4でmod rewriteを使う" />
      <page pageid="130" ns="0" title="apachectl" />
      <page pageid="131" ns="0" title="httpd" />
    </pages>
  </query>
</api>