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>
    <recentchanges rccontinue="20170111233632|448" />
  </query-continue>
  <query>
    <recentchanges>
      <rc type="edit" ns="0" title="Train Derailment at Haywards, 1943" pageid="12" revid="452" old_revid="451" rcid="458" timestamp="2017-02-20T01:47:44Z" />
      <rc type="edit" ns="0" title="Train Derailment at Haywards, 1943" pageid="12" revid="451" old_revid="450" rcid="457" timestamp="2017-02-20T01:33:08Z" />
      <rc type="edit" ns="0" title="Train Derailment at Haywards, 1943" pageid="12" revid="450" old_revid="449" rcid="456" timestamp="2017-02-20T01:30:09Z" />
      <rc type="edit" ns="0" title="Train Derailment at Haywards, 1943" pageid="12" revid="449" old_revid="447" rcid="455" timestamp="2017-02-20T01:07:13Z" />
      <rc type="log" ns="6" title="File:Aerial View Silverstream (Part showing Manor&#039;s Park) ARCH71770.JPG" pageid="163" revid="0" old_revid="0" rcid="454" timestamp="2017-02-20T00:51:36Z" />
      <rc type="edit" ns="0" title="Train Derailment at Haywards, 1943" pageid="12" revid="447" old_revid="446" rcid="453" timestamp="2017-01-11T23:59:31Z" />
      <rc type="edit" ns="0" title="Train Derailment at Haywards, 1943" pageid="12" revid="446" old_revid="445" rcid="452" timestamp="2017-01-11T23:56:13Z" />
      <rc type="edit" ns="0" title="Train Derailment at Haywards, 1943" pageid="12" revid="445" old_revid="444" rcid="451" timestamp="2017-01-11T23:52:41Z" />
      <rc type="edit" ns="0" title="Train Derailment at Haywards, 1943" pageid="12" revid="444" old_revid="443" rcid="450" timestamp="2017-01-11T23:48:31Z" />
      <rc type="edit" ns="0" title="Train Derailment at Haywards, 1943" pageid="12" revid="443" old_revid="442" rcid="449" timestamp="2017-01-11T23:44:43Z" />
    </recentchanges>
  </query>
</api>