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>
    <allredirects garcontinue="File_Transfer_Protocol" />
  </query-continue>
  <query>
    <pages>
      <page pageid="90" ns="0" title="BINコード" />
      <page pageid="718" ns="0" title="Basic Input/Output System" />
      <page pageid="861" ns="0" title="Burp Suite" />
      <page pageid="954" ns="0" title="CVE-2014-0160 OpenSSL Heartbleed" />
      <page pageid="982" ns="0" title="CVE-2014-3566 SSL 3.0 脆弱性 POODLE" />
      <page pageid="901" ns="0" title="C言語" />
      <page pageid="957" ns="0" title="Digital Signature Algorithm" />
      <page pageid="222" ns="0" title="DoS攻撃" />
      <page pageid="288" ns="0" title="Domain Name System" />
      <page pageid="437" ns="0" title="Enhanced Mitigation Experience Toolkit" />
    </pages>
  </query>
</api>