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="20180211100813|273" />
  </query-continue>
  <query>
    <recentchanges>
      <rc type="edit" ns="0" title="メモリの動的な確保と解放" pageid="24" revid="283" old_revid="270" rcid="283" timestamp="2018-04-22T03:03:04Z" />
      <rc type="edit" ns="0" title="if文の書き方" pageid="90" revid="282" old_revid="281" rcid="282" timestamp="2018-03-19T11:44:18Z" />
      <rc type="edit" ns="0" title="if文の書き方" pageid="90" revid="281" old_revid="280" rcid="281" timestamp="2018-03-18T13:07:22Z" />
      <rc type="new" ns="0" title="if文の書き方" pageid="90" revid="280" old_revid="0" rcid="280" timestamp="2018-03-18T13:05:31Z" />
      <rc type="edit" ns="0" title="C言語解説" pageid="4" revid="279" old_revid="272" rcid="279" timestamp="2018-03-18T12:35:51Z" />
      <rc type="edit" ns="0" title="C言語でUUIDを生成する方法" pageid="89" revid="278" old_revid="277" rcid="278" timestamp="2018-03-17T09:05:09Z" />
      <rc type="edit" ns="0" title="C言語でUUIDを生成する方法" pageid="89" revid="277" old_revid="276" rcid="277" timestamp="2018-03-17T06:38:44Z" />
      <rc type="new" ns="0" title="C言語でUUIDを生成する方法" pageid="89" revid="276" old_revid="0" rcid="276" timestamp="2018-03-17T05:36:32Z" />
      <rc type="edit" ns="0" title="Cライブラリ" pageid="25" revid="275" old_revid="274" rcid="275" timestamp="2018-03-17T05:12:34Z" />
      <rc type="edit" ns="0" title="Cライブラリ" pageid="25" revid="274" old_revid="267" rcid="274" timestamp="2018-03-17T05:10:01Z" />
    </recentchanges>
  </query>
</api>