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>
    <random>
      <page id="4422" ns="0" title="Z80 Optimization" />
      <page id="3051" ns="0" title="奥运闭幕式竟来自纸上谈兵" />
    </random>
  </query>
</api>