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="20150226192456|373" />
  </query-continue>
  <query>
    <recentchanges>
      <rc type="edit" ns="8" title="MediaWiki:Sidebar" pageid="4" revid="379" old_revid="378" rcid="383" timestamp="2016-09-09T06:59:35Z" />
      <rc type="edit" ns="8" title="MediaWiki:Sidebar" pageid="4" revid="378" old_revid="377" rcid="382" timestamp="2016-02-03T17:28:37Z" />
      <rc type="edit" ns="8" title="MediaWiki:Sidebar" pageid="4" revid="377" old_revid="376" rcid="381" timestamp="2016-02-03T17:23:44Z" />
      <rc type="edit" ns="8" title="MediaWiki:Sidebar" pageid="4" revid="376" old_revid="364" rcid="380" timestamp="2015-08-08T09:54:49Z" />
      <rc type="edit" ns="10" title="Template:廣告模版" pageid="16" revid="375" old_revid="372" rcid="379" timestamp="2015-07-02T14:35:53Z" />
      <rc type="log" ns="6" title="File:商情百科20150702.gif" pageid="146" revid="0" old_revid="0" rcid="378" timestamp="2015-07-02T14:35:40Z" />
      <rc type="log" ns="6" title="File:商情百科20150702.gif" pageid="146" revid="0" old_revid="0" rcid="377" timestamp="2015-07-02T14:35:23Z" />
      <rc type="edit" ns="10" title="Template:廣告模版" pageid="16" revid="372" old_revid="369" rcid="376" timestamp="2015-06-24T15:18:18Z" />
      <rc type="log" ns="6" title="File:鄭鴻文(書法家).jpg" pageid="145" revid="0" old_revid="0" rcid="375" timestamp="2015-06-24T15:17:53Z" />
      <rc type="log" ns="6" title="File:鄭鴻文(書法家).jpg" pageid="145" revid="0" old_revid="0" rcid="374" timestamp="2015-06-24T15:17:23Z" />
    </recentchanges>
  </query>
</api>