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>
    <allimages gaicontinue="Ferraris_meter_dubbel_tarief.jpg" />
  </query-continue>
  <query>
    <pages>
      <page pageid="84" ns="6" title="Bestand:3Tier-Global-Mean-Wind-Speed.jpg" />
      <page pageid="176" ns="6" title="Bestand:Aardolieproduktie nederland.svg" />
      <page pageid="4078" ns="6" title="Bestand:Belgium icon.png" />
      <page pageid="4017" ns="6" title="Bestand:Centrosolar.png" />
      <page pageid="4082" ns="6" title="Bestand:Checkmark 12x12.png" />
      <page pageid="4081" ns="6" title="Bestand:Checkmark 16x16.png" />
      <page pageid="10" ns="6" title="Bestand:DeWiki-Logo.jpg" />
      <page pageid="113" ns="6" title="Bestand:Delta Solivia 3.3.jpg" />
      <page pageid="109" ns="6" title="Bestand:Eenfase-vs-driefase-invoeding.png" />
      <page pageid="101" ns="6" title="Bestand:Enercon E-126 CC-attribute JakoJellema@Flickr.jpg" />
    </pages>
  </query>
</api>