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>
    <pages>
      <page pageid="239" ns="0" title="Contributors" />
      <page pageid="281" ns="0" title="Document RGLM tools" />
      <page pageid="359" ns="0" title="G16 Workshop on Modeling the Age of Water" />
      <page pageid="361" ns="0" title="Logistics" />
      <page pageid="466" ns="0" title="2014 first Steering Committee Meeting" />
      <page pageid="1310" ns="0" title="GLM Week 2015 March UW" />
    </pages>
  </query>
</api>