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>
    <allfileusages gafcontinue="B0985_7.jpg|466" />
  </query-continue>
  <query>
    <pages>
      <page pageid="466" ns="0" title="청주 용화사 석조불상군" />
      <page pageid="2503" ns="0" title="국화차" />
      <page pageid="10778" ns="0" title="산채향기" />
      <page pageid="11006" ns="0" title="한국 근현대사 박물관" />
      <page pageid="16737" ns="0" title="B-52" />
    </pages>
  </query>
</api>