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 aicontinue="Bolzano_2005_05_circ10195_2005.pdf" />
  </query-continue>
  <query>
    <allimages>
      <img name="Basilicata.png" timestamp="2014-09-25T13:15:50Z" url="http://wiki.inmp.it/wiki/images/Basilicata.png" descriptionurl="http://wiki.inmp.it/wiki/index.php/File:Basilicata.png" ns="6" title="File:Basilicata.png" />
      <img name="Basilicata_1996_DOCUMENT_FILE_553492.pdf" timestamp="2016-12-21T11:26:48Z" url="http://wiki.inmp.it/wiki/images/Basilicata_1996_DOCUMENT_FILE_553492.pdf" descriptionurl="http://wiki.inmp.it/wiki/index.php/File:Basilicata_1996_DOCUMENT_FILE_553492.pdf" ns="6" title="File:Basilicata 1996 DOCUMENT FILE 553492.pdf" />
      <img name="Basilicata_2006_Linee_guida_stranieri_non_UE.pdf" timestamp="2016-12-20T11:17:23Z" url="http://wiki.inmp.it/wiki/images/Basilicata_2006_Linee_guida_stranieri_non_UE.pdf" descriptionurl="http://wiki.inmp.it/wiki/index.php/File:Basilicata_2006_Linee_guida_stranieri_non_UE.pdf" ns="6" title="File:Basilicata 2006 Linee guida stranieri non UE.pdf" />
      <img name="Basilicata_2013_2013.DGR_529linee_x_stranieri.pdf" timestamp="2016-12-21T11:23:08Z" url="http://wiki.inmp.it/wiki/images/Basilicata_2013_2013.DGR_529linee_x_stranieri.pdf" descriptionurl="http://wiki.inmp.it/wiki/index.php/File:Basilicata_2013_2013.DGR_529linee_x_stranieri.pdf" ns="6" title="File:Basilicata 2013 2013.DGR 529linee x stranieri.pdf" />
      <img name="Basilicata_2013_DOCUMENT_FILE_2933785.pdf" timestamp="2016-12-20T11:44:12Z" url="http://wiki.inmp.it/wiki/images/Basilicata_2013_DOCUMENT_FILE_2933785.pdf" descriptionurl="http://wiki.inmp.it/wiki/index.php/File:Basilicata_2013_DOCUMENT_FILE_2933785.pdf" ns="6" title="File:Basilicata 2013 DOCUMENT FILE 2933785.pdf" />
      <img name="Basilicata_2014_Delibera_n°_20140000593.pdf" timestamp="2016-12-21T11:28:11Z" url="http://wiki.inmp.it/wiki/images/Basilicata_2014_Delibera_n%C2%B0_20140000593.pdf" descriptionurl="http://wiki.inmp.it/wiki/index.php/File:Basilicata_2014_Delibera_n%C2%B0_20140000593.pdf" ns="6" title="File:Basilicata 2014 Delibera n° 20140000593.pdf" />
      <img name="Basilicata_2014_Nota_Prot_118143_13AB_del_21_Luglio_2014.pdf" timestamp="2016-12-20T11:16:41Z" url="http://wiki.inmp.it/wiki/images/Basilicata_2014_Nota_Prot_118143_13AB_del_21_Luglio_2014.pdf" descriptionurl="http://wiki.inmp.it/wiki/index.php/File:Basilicata_2014_Nota_Prot_118143_13AB_del_21_Luglio_2014.pdf" ns="6" title="File:Basilicata 2014 Nota Prot 118143 13AB del 21 Luglio 2014.pdf" />
      <img name="Basilicata_dna_DOCUMENT_FILE_1654659.pdf" timestamp="2016-12-20T11:41:08Z" url="http://wiki.inmp.it/wiki/images/Basilicata_dna_DOCUMENT_FILE_1654659.pdf" descriptionurl="http://wiki.inmp.it/wiki/index.php/File:Basilicata_dna_DOCUMENT_FILE_1654659.pdf" ns="6" title="File:Basilicata dna DOCUMENT FILE 1654659.pdf" />
      <img name="Basilicata_small.png" timestamp="2016-11-11T11:14:05Z" url="http://wiki.inmp.it/wiki/images/Basilicata_small.png" descriptionurl="http://wiki.inmp.it/wiki/index.php/File:Basilicata_small.png" ns="6" title="File:Basilicata small.png" />
      <img name="Bolzano.png" timestamp="2014-09-25T13:16:39Z" url="http://wiki.inmp.it/wiki/images/Bolzano.png" descriptionurl="http://wiki.inmp.it/wiki/index.php/File:Bolzano.png" ns="6" title="File:Bolzano.png" />
    </allimages>
  </query>
</api>