You are looking at the HTML representation of the DBG 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 DBG format, set format=dbg.
See the complete documentation, or API help for more information. 
array (
  'query' => 
  array (
    'namespaces' => 
    array (
      -2 => 
      array (
        'id' => -2,
        'case' => 'first-letter',
        '*' => 'Media',
        'canonical' => 'Media',
      ),
      -1 => 
      array (
        'id' => -1,
        'case' => 'first-letter',
        '*' => 'Especial',
        'canonical' => 'Special',
      ),
      0 => 
      array (
        'id' => 0,
        'case' => 'first-letter',
        '*' => '',
        'content' => '',
      ),
      1 => 
      array (
        'id' => 1,
        'case' => 'first-letter',
        '*' => 'Discussió',
        'subpages' => '',
        'canonical' => 'Talk',
      ),
      2 => 
      array (
        'id' => 2,
        'case' => 'first-letter',
        '*' => 'Usuari',
        'subpages' => '',
        'canonical' => 'User',
      ),
      3 => 
      array (
        'id' => 3,
        'case' => 'first-letter',
        '*' => 'Usuari Discussió',
        'subpages' => '',
        'canonical' => 'User talk',
      ),
      4 => 
      array (
        'id' => 4,
        'case' => 'first-letter',
        '*' => 'Rosespedia',
        'subpages' => '',
        'canonical' => 'Project',
      ),
      5 => 
      array (
        'id' => 5,
        'case' => 'first-letter',
        '*' => 'Rosespedia Discussió',
        'subpages' => '',
        'canonical' => 'Project talk',
      ),
      6 => 
      array (
        'id' => 6,
        'case' => 'first-letter',
        '*' => 'Fitxer',
        'canonical' => 'File',
      ),
      7 => 
      array (
        'id' => 7,
        'case' => 'first-letter',
        '*' => 'Fitxer Discussió',
        'subpages' => '',
        'canonical' => 'File talk',
      ),
      8 => 
      array (
        'id' => 8,
        'case' => 'first-letter',
        '*' => 'MediaWiki',
        'subpages' => '',
        'canonical' => 'MediaWiki',
      ),
      9 => 
      array (
        'id' => 9,
        'case' => 'first-letter',
        '*' => 'MediaWiki Discussió',
        'subpages' => '',
        'canonical' => 'MediaWiki talk',
      ),
      10 => 
      array (
        'id' => 10,
        'case' => 'first-letter',
        '*' => 'Plantilla',
        'canonical' => 'Template',
      ),
      11 => 
      array (
        'id' => 11,
        'case' => 'first-letter',
        '*' => 'Plantilla Discussió',
        'subpages' => '',
        'canonical' => 'Template talk',
      ),
      12 => 
      array (
        'id' => 12,
        'case' => 'first-letter',
        '*' => 'Ajuda',
        'subpages' => '',
        'canonical' => 'Help',
      ),
      13 => 
      array (
        'id' => 13,
        'case' => 'first-letter',
        '*' => 'Ajuda Discussió',
        'subpages' => '',
        'canonical' => 'Help talk',
      ),
      14 => 
      array (
        'id' => 14,
        'case' => 'first-letter',
        '*' => 'Categoria',
        'canonical' => 'Category',
      ),
      15 => 
      array (
        'id' => 15,
        'case' => 'first-letter',
        '*' => 'Categoria Discussió',
        'subpages' => '',
        'canonical' => 'Category talk',
      ),
      420 => 
      array (
        'id' => 420,
        'case' => 'first-letter',
        '*' => 'Layer',
        'canonical' => 'Layer',
      ),
      421 => 
      array (
        'id' => 421,
        'case' => 'first-letter',
        '*' => 'Layer talk',
        'canonical' => 'Layer talk',
      ),
    ),
  ),
)