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="etcd" />
  </query-continue>
  <query>
    <pages>
      <page ns="0" title="Docker" missing="" />
      <page ns="0" title="NewArticle" missing="" />
      <page pageid="5" ns="0" title="CoreOS" />
      <page pageid="4" ns="0" title="CoreOS Container LinuxをVMwareで動かす" />
      <page pageid="9" ns="0" title="Eclipse Che" />
      <page pageid="20" ns="0" title="GNU parallel" />
      <page pageid="11" ns="0" title="LinuxKit" />
      <page pageid="12" ns="0" title="Moby" />
      <page pageid="19" ns="0" title="PhantomJSのQXcbConnection Could not connect to displayを解決する方法" />
      <page pageid="14" ns="0" title="curlでリダイレクトの遷移を追う方法" />
    </pages>
  </query>
</api>