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="HEXCraft" />
  </query-continue>
  <query>
    <pages>
      <page pageid="511" ns="0" title="Block of Hexorium Crystal" />
      <page pageid="1023" ns="0" title="Concentric Hexorium Block" />
      <page pageid="1689" ns="0" title="Conversion Computer" />
      <page pageid="403" ns="0" title="Energized Hexorium" />
      <page pageid="528" ns="0" title="Energized Hexorium Monolith" />
      <page pageid="1359" ns="0" title="Energy Node Core" />
      <page pageid="495" ns="0" title="Engineered Hexorium Block" />
      <page pageid="501" ns="0" title="Framed Hexorium Block" />
      <page pageid="1474" ns="0" title="Glowing Hexorium-Coated Stone" />
      <page pageid="1024" ns="0" title="Glowing Hexorium Glass" />
    </pages>
  </query>
</api>