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>
    <allredirects garcontinue="Canon_1D_Mark_III|845" />
  </query-continue>
  <query>
    <pages>
      <page pageid="841" ns="0" title="1D Mark III" />
      <page pageid="842" ns="0" title="1D III" />
      <page pageid="843" ns="0" title="1DIII" />
      <page pageid="844" ns="0" title="Canon 1D III" />
      <page pageid="846" ns="0" title="1D Mark II" />
      <page pageid="847" ns="0" title="1D II" />
      <page pageid="848" ns="0" title="1DII" />
      <page pageid="849" ns="0" title="Canon 1D II" />
      <page pageid="850" ns="0" title="Canon 1DII" />
      <page pageid="947" ns="0" title="1D2" />
    </pages>
  </query>
</api>