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"?>
    <alllinks galcontinue="Castrovalva" />
      <page ns="0" title="Basic Tessellation Exercises" missing="" />
      <page pageid="3332" ns="0" title="Balcony" />
      <page pageid="2168" ns="0" title="Beautiful (Flor de Pascua)" />
      <page pageid="2043" ns="0" title="Belvedere" />
      <page pageid="3266" ns="0" title="Bond of Union" />
      <page pageid="3634" ns="0" title="Border Pattern Project" />
      <page pageid="2357" ns="0" title="Butterflies" />
      <page pageid="2356" ns="0" title="Butterflies (Color)" />
      <page pageid="2116" ns="0" title="Carte Blanche" />
      <page pageid="3314" ns="0" title="Carved Polyhedron with Flowers" />