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>
    <pages>
      <page pageid="5107" ns="0" title="Test">
        <revisions>
          <rev contentformat="text/x-wiki" contentmodel="wikitext" xml:space="preserve">&lt;graphviz format='svg'&gt;
digraph SDKLayers
{
    graph [
        label = &quot;PDF-XChange SDK Structure&quot;
        labelloc = t
        
        ordering = &quot;in&quot;
        
        ranksep = 0.65
#        nodesep = 0.10
        rankdir = TB
        fontname=&quot;serif&quot;
    ]
    
    node [
        fontsize=12
        fontname=&quot;serif&quot;
        shape=&quot;note&quot;
        style=filled
        fillcolor=&quot;#ccebc5&quot;
        dir=none
    ]
    
    edge [
        dir=none
    ]
#    splines=ortho

    PXV [label=&quot;PDF Editor Layer\n[PXV]&quot;, URL=&quot;PXV:PXV&quot;, shape=&quot;folder&quot;, fillcolor=&quot;#fed9a6&quot;];
    UIX [label=&quot;UI Layer\n[UIX]&quot;, URL=&quot;PXV:UIX&quot;];

    subgraph cluster_B
    {
        label = &quot;PXC-XChange Editor SDK&quot;;
        style = rounded;

        subgraph cluster_A
        {
            label = &quot;PXC-XChange Core API&quot;;
            bgcolor = gray95;
            color = gray45;
            style = dashed;
            ranksep = 0.05
            nodesep = 0.01

            PXC [label=&quot;PDF Core Layer\n[PXC]&quot;, URL=&quot;PXV:PXC&quot;, shape=&quot;folder&quot;, fillcolor=&quot;#fddaec&quot;];
            PXS [label=&quot;PDF Structure Layer\n[PXS]&quot;, URL=&quot;PXV:PXS&quot;];
            AFS [label=&quot;File Systems Layer\n[AFS]&quot;, URL=&quot;PXV:AFS&quot;];
            IXC [label=&quot;Images Core Layer\n[IXC]&quot;, URL=&quot;PXV:IXC&quot;];
            AUX [label=&quot;Common Layer\n[AUX]&quot;, URL=&quot;PXV:AUX&quot;];
 
            PXC -&gt; PXS;
            PXC -&gt; AFS;
            PXC -&gt; IXC;
            PXC -&gt; AUX;
        }
        {
            PXV -&gt; PXC
        }
        {
            PXV -&gt; UIX
        }
    }
}
&lt;/graphviz&gt;</rev>
        </revisions>
      </page>
    </pages>
  </query>
</api>