You are looking at the HTML representation of the XML format.
HTML is good for debugging, but probably is not suitable for your application.
See complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query>
    <allpages>
      <p pageid="581" ns="0" title="Biomass Briquetting Plant-Energy Efficient Source Of Energy" />
      <p pageid="589" ns="0" title="Biomass Business Opportunities in Vietnam" />
      <p pageid="407" ns="0" title="Book Creator" />
      <p pageid="282" ns="0" title="Change Titles of Articles" />
      <p pageid="401" ns="0" title="Copy from Other Wikis" />
      <p pageid="276" ns="0" title="Copy from Word" />
      <p pageid="275" ns="0" title="Create Bullet Points and Numbered Lists" />
      <p pageid="109" ns="0" title="Create a New Article" />
      <p pageid="439" ns="0" title="Delete Articles" />
      <p pageid="440" ns="0" title="Deletion Policy" />
    </allpages>
  </query>
  <query-continue>
    <allpages apfrom="Discussions" />
  </query-continue>
</api>