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>
    <allpages apcontinue="Supernodoa_eraikitzen" />
  </query-continue>
  <query>
    <allpages>
      <p pageid="6" ns="0" title="IP helbideak" />
      <p pageid="21" ns="0" title="Inguruan sor daitezkeen jarduera ekonomikoak" />
      <p pageid="17" ns="0" title="Internet gabe ze interes dauka honek?" />
      <p pageid="14" ns="0" title="Lehen super-nodoa larrabetzun" />
      <p pageid="13" ns="0" title="MikroTik RouterBOARD 750G" />
      <p pageid="44" ns="0" title="Mikrotik RouterBoard 750" />
      <p pageid="12" ns="0" title="Mikrotik RouterBoard 750/eu" />
      <p pageid="18" ns="0" title="Nola antolatzen/kudeatzen da Guifi.net?" />
      <p pageid="19" ns="0" title="Nola konektatuko naiz Internetera?" />
      <p pageid="20" ns="0" title="Osasunarentzako arriskurik dago?" />
    </allpages>
  </query>
</api>