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>
    <alllinks galcontinue="List_Available_Phone_Numbers" />
  </query-continue>
  <query>
    <pages>
      <page pageid="10" ns="0" title="Get Domain Info" />
      <page pageid="12" ns="0" title="Get Credit Limit" />
      <page pageid="13" ns="0" title="Get Sender Names" />
      <page pageid="14" ns="0" title="Calculate Credits" />
      <page pageid="15" ns="0" title="Get History" />
      <page pageid="17" ns="0" title="Delete Sscheduled SMS" />
      <page pageid="18" ns="0" title="Changelog" />
      <page pageid="21" ns="0" title="Get Line List" />
      <page pageid="23" ns="0" title="Get Line Details" />
      <page pageid="24" ns="0" title="Get Calls History" />
    </pages>
  </query>
</api>