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>
    <blocks>
      <block id="66" user="Gisele BOULLIER" by="Marie BOUCHER" timestamp="2014-06-08T07:19:34Z" expiry="infinity" reason="CONFUSION de prénom" nocreate="" autoblock="" noemail="" />
      <block id="64" user="RobertLeCam" by="MORO" timestamp="2014-05-14T12:20:31Z" expiry="infinity" reason="Double inscription" nocreate="" autoblock="" noemail="" />
      <block id="62" user="Daniel GUÉGAN" by="MORO" timestamp="2014-02-12T15:05:09Z" expiry="infinity" reason="problème accent et clavier" nocreate="" />
      <block id="61" user="NadineLeDily" by="MORO" timestamp="2014-02-08T08:35:37Z" expiry="infinity" reason="double création de compte" nocreate="" />
      <block id="51" user="VivianIibstrtgm" by="MORO" timestamp="2013-12-14T09:36:17Z" expiry="infinity" reason="" nocreate="" autoblock="" />
      <block id="49" user="YvonneMulquin" by="MORO" timestamp="2013-12-14T08:36:25Z" expiry="infinity" reason="" nocreate="" autoblock="" />
      <block id="47" user="YaniraDillion" by="MORO" timestamp="2013-12-14T08:36:10Z" expiry="infinity" reason="" nocreate="" autoblock="" />
      <block id="45" user="OsvaldoBlackbur" by="MORO" timestamp="2013-12-14T08:35:55Z" expiry="infinity" reason="" nocreate="" autoblock="" />
      <block id="44" user="NannieHarton" by="MORO" timestamp="2013-12-14T08:35:36Z" expiry="infinity" reason="" nocreate="" autoblock="" />
      <block id="42" user="MitchFriedmann" by="MORO" timestamp="2013-12-14T08:35:23Z" expiry="infinity" reason="" nocreate="" autoblock="" />
    </blocks>
  </query>
  <query-continue>
    <blocks bkstart="2013-12-14T08:35:09Z" />
  </query-continue>
</api>