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>
    <pageswithprop pwpcontinue="9711" />
  </query-continue>
  <query>
    <pageswithprop>
      <page pageid="1557" ns="0" title="Lonelygirl15" value="lonelygirl15" />
      <page pageid="2061" ns="0" title="An update of sorts" value="an update of sorts" />
      <page pageid="2062" ns="0" title="My lonesome update for mid October" value="my lonesome update for mid October" />
      <page pageid="5948" ns="0" title="Lonelygirl15 product placement" value="lonelygirl15 product placement" />
      <page pageid="9619" ns="0" title="Lonelygirl15 Season 1 Recap" value="lonelygirl15 Season 1 Recap" />
      <page pageid="9688" ns="0" title="Lonelygirl15 Season Finale 1 of 12 - 8 am" value="lonelygirl15 Season Finale 1 of 12 - 8 am" />
      <page pageid="9695" ns="0" title="Lonelygirl15 Season Finale 2 of 12 - 9 am" value="lonelygirl15 Season Finale 2 of 12 - 9 am" />
      <page pageid="9701" ns="0" title="Lonelygirl15 Season Finale 11 of 12 - 6 pm" value="lonelygirl15 Season Finale 11 of 12 - 6 pm" />
      <page pageid="9702" ns="0" title="Lonelygirl15 Season Finale 12 of 12 - 7 pm" value="lonelygirl15 Season Finale 12 of 12 - 7 pm" />
      <page pageid="9710" ns="0" title="Lonelygirl15 Season Finale 9 of 12 - 4 pm" value="lonelygirl15 Season Finale 9 of 12 - 4 pm" />
    </pageswithprop>
  </query>
</api>