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="Myst_INIT_resources" />
  </query-continue>
  <query>
    <pages>
      <page pageid="342" ns="0" title="CARD" />
      <page pageid="602" ns="0" title="CLRC" />
      <page pageid="832" ns="0" title="Mohawk Bitmaps" />
      <page pageid="672" ns="0" title="Mohawk MIDI" />
      <page pageid="652" ns="0" title="Mohawk Sounds" />
      <page pageid="22" ns="0" title="Mohawk archive format" />
      <page pageid="572" ns="0" title="Myst CLRC resources" />
      <page pageid="682" ns="0" title="Myst EXIT resources" />
      <page pageid="632" ns="0" title="Myst HELP resources" />
      <page pageid="702" ns="0" title="Myst HINT resources" />
    </pages>
  </query>
</api>