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="HEXCraft" />
  </query-continue>
  <query>
    <allredirects>
      <r ns="0" title="Block of Hexorium Crystal" />
      <r ns="0" title="Concentric Hexorium Block" />
      <r ns="0" title="Conversion Computer" />
      <r ns="0" title="Energized Hexorium" />
      <r ns="0" title="Energized Hexorium Monolith" />
      <r ns="0" title="Energy Node Core" />
      <r ns="0" title="Engineered Hexorium Block" />
      <r ns="0" title="Framed Hexorium Block" />
      <r ns="0" title="Glowing Hexorium-Coated Stone" />
      <r ns="0" title="Glowing Hexorium Glass" />
    </allredirects>
  </query>
</api>