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>
    <allpages>
      <p pageid="20" ns="0" title="Client" />
      <p pageid="46" ns="0" title="Eclips pics" />
      <p pageid="54" ns="0" title="Ethershield/Modbus" />
      <p pageid="50" ns="0" title="Example" />
      <p pageid="58" ns="0" title="Execute a script" />
      <p pageid="56" ns="0" title="From 32 bit to 64 bit" />
      <p pageid="77" ns="0" title="Function Object ObjectGraph" />
      <p pageid="68" ns="0" title="Function Object With C Code" />
      <p pageid="8" ns="0" title="Hilscher CIF 50-PB" />
      <p pageid="4" ns="0" title="How to install" />
    </allpages>
  </query>
  <query-continue>
    <allpages apcontinue="How_to_route_pipes" />
  </query-continue>
</api>