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="Calibrate_lake_and_catchment_models" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="447" ns="0" title="Basic Task States" />
      <p pageid="1006" ns="0" title="Beverly Wemple" />
      <p pageid="998" ns="0" title="Beverly Wemple G16 Workshop tasks" />
      <p pageid="130" ns="0" title="Bibliography" />
      <p pageid="988" ns="0" title="Bomchul Kim" />
      <p pageid="980" ns="0" title="Bomchul Kim G16 Workshop tasks" />
      <p pageid="997" ns="0" title="Bruce Hargreaves" />
      <p pageid="989" ns="0" title="Bruce Hargreaves G16 Workshop tasks" />
      <p pageid="261" ns="0" title="Calibrate PIHM for NTL" />
      <p pageid="287" ns="0" title="Calibrate dissolved oxygen" />
    </allpages>
  </query>
</api>