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>
    <allpages apcontinue="Savegame_File-Listing" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="10" ns="0" title="Black Hole" />
      <p pageid="27" ns="0" title="Editing Savegames" />
      <p pageid="25" ns="0" title="How to add new ship models using UE" />
      <p pageid="29" ns="0" title="Large Map Generation Chart and tutorial for UE" />
      <p pageid="31" ns="0" title="Library of Subroutines" />
      <p pageid="30" ns="0" title="List of known Dynamic Variables" />
      <p pageid="1" ns="0" title="Main Page" />
      <p pageid="15" ns="0" title="Nebula" />
      <p pageid="12" ns="0" title="Neutron Star" />
      <p pageid="13" ns="0" title="Radio Pulsar" />
    </allpages>
  </query>
</api>