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="367300-Luer_adapter.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="636" ns="6" title="Bestand:350C-eSwab.png" />
      <page pageid="637" ns="6" title="Bestand:360211-Vac Needle 22G.png" />
      <page pageid="638" ns="6" title="Bestand:360213-Vac Needle 21G.png" />
      <page pageid="639" ns="6" title="Bestand:360215-Vac Needle 20G.png" />
      <page pageid="640" ns="6" title="Bestand:363706 EDTA micro.png" />
      <page pageid="641" ns="6" title="Bestand:365968 Serum micro.png" />
      <page pageid="642" ns="6" title="Bestand:365986-Heparin micro.png" />
      <page pageid="643" ns="6" title="Bestand:365993-NaF micro.png" />
      <page pageid="644" ns="6" title="Bestand:367282-Butterfly 21G.png" />
      <page pageid="645" ns="6" title="Bestand:367284-Butterfly 23G.png" />
    </pages>
  </query>
</api>