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 arcontinue="Blueco_Incidence|1974" />
  </query-continue>
  <query>
    <allredirects>
      <r fromid="4599" ns="0" title="Basement Rituals Vol 11 Bronze Edition (Album)" />
      <r fromid="3200" ns="0" title="Ben Bonnett" />
      <r fromid="1665" ns="0" title="Bill Houston" />
      <r fromid="2551" ns="0" title="Bitter Morning" />
      <r fromid="1654" ns="0" title="Black Pirates Pub" />
      <r fromid="3061" ns="0" title="Black Pirates Pub" />
      <r fromid="3178" ns="0" title="Black Pirates Pub" />
      <r fromid="147" ns="0" title="Blood Pool" />
      <r fromid="2490" ns="0" title="Blue Monday Jazz Trio" />
      <r fromid="3040" ns="0" title="Blue Pretenders" />
    </allredirects>
  </query>
</api>