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>
    <alllinks galcontinue="XD|1" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="首頁" />
      <page pageid="3" ns="0" title="OVH" />
      <page pageid="4" ns="0" title="檔案下載需知" />
      <page pageid="10" ns="0" title="BDMV外掛字幕結構" />
      <page pageid="20" ns="0" title="常見問答" />
    </pages>
  </query>
</api>