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>
    <alllinks galcontinue="CSS_basics" />
  </query-continue>
  <query>
    <pages>
      <page ns="0" title="Backups en Windows" missing="" />
      <page ns="0" title="Benchmarking" missing="" />
      <page pageid="475" ns="0" title="Backups en GNU/Linux" />
      <page pageid="318" ns="0" title="Bases de dades" />
      <page pageid="469" ns="0" title="Bash script" />
      <page pageid="494" ns="0" title="Batalla naval en PHP" />
      <page pageid="421" ns="0" title="Bones pràctiques de programació" />
      <page pageid="313" ns="0" title="Buildout" />
      <page pageid="526" ns="0" title="CMS" />
      <page pageid="257" ns="0" title="CMS backup and restoring" />
    </pages>
  </query>
</api>