You are looking at the HTML representation of the XML format.
HTML is good for debugging, but probably is not suitable for your application.
See complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query>
    <allpages>
      <p pageid="54" ns="0" title="BMX6" />
      <p pageid="53" ns="0" title="Captive portal" />
      <p pageid="63" ns="0" title="Check list installazioni" />
      <p pageid="52" ns="0" title="CompilareDaOpenWrt" />
      <p pageid="82" ns="0" title="CompilareDaOpenWrt-TRUNK" />
      <p pageid="83" ns="0" title="Costi antenne" />
      <p pageid="76" ns="0" title="DHCP per NinuxBO" />
      <p pageid="84" ns="0" title="Downgrade del firmware" />
      <p pageid="105" ns="0" title="Errore profilo LibreMesh encrypt" />
      <p pageid="107" ns="0" title="Errore profilo LibreMesh encrypt nano" />
    </allpages>
  </query>
  <query-continue>
    <allpages apfrom="Esperimenti wifi" />
  </query-continue>
</api>