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>
    <links gplcontinue="1|0|IBHLink_S5++:SIMATIC®_S5_for_Windows®" />
  </query-continue>
  <query>
    <pages>
      <page pageid="590" ns="0" title="IBHLink:S7++:SINAMICS G120 with IBHLink S7++" contentmodel="wikitext" pagelanguage="en" touched="2013-10-28T08:39:03Z" lastrevid="1521" counter="3684" length="361" />
      <page pageid="593" ns="0" title="IBHLink S5++:Beckhoff TwinCAT PLC with IBHLink S5++" contentmodel="wikitext" pagelanguage="en" touched="2013-10-28T11:58:07Z" lastrevid="1527" counter="2156" length="488" new="" />
      <page pageid="601" ns="0" title="IBHLink S5++:Network configuration via USB" contentmodel="wikitext" pagelanguage="en" touched="2014-01-28T13:22:01Z" lastrevid="1552" counter="5998" length="932" />
      <page pageid="896" ns="0" title="IBHLink S5++:S7 1500 PLC with IBHLink S7++" contentmodel="wikitext" pagelanguage="en" touched="2019-02-20T14:31:00Z" lastrevid="2031" counter="2686" length="806" new="" />
      <page pageid="718" ns="0" title="IBHLink S5++:S7 PLC with IBHLink S7++" contentmodel="wikitext" pagelanguage="en" touched="2015-07-02T07:27:46Z" lastrevid="1732" counter="3820" length="832" new="" />
      <page pageid="84" ns="0" title="IBHLink S5++:SIMATIC® S5 Elipse SCADA" contentmodel="wikitext" pagelanguage="en" touched="2013-09-19T10:04:16Z" lastrevid="1488" counter="5928" length="1805" />
      <page pageid="866" ns="0" title="IBHLink S5++:SIMATIC® S5 Intouch" contentmodel="wikitext" pagelanguage="en" touched="2018-10-29T12:16:00Z" lastrevid="1983" counter="1722" length="1424" new="" />
      <page pageid="82" ns="0" title="IBHLink S5++:SIMATIC® S5 PLC PcVue" contentmodel="wikitext" pagelanguage="en" touched="2013-09-19T10:03:22Z" lastrevid="1487" counter="6107" length="2248" />
      <page pageid="244" ns="0" title="IBHLink S5++:SIMATIC® S5 TIA Portal V11 WinCC flexible" contentmodel="wikitext" pagelanguage="en" touched="2013-09-19T09:37:26Z" lastrevid="1485" counter="10169" length="4245" />
      <page pageid="242" ns="0" title="IBHLink S5++:SIMATIC® S5 WinCC flexible" contentmodel="wikitext" pagelanguage="en" touched="2013-09-19T10:02:09Z" lastrevid="1486" counter="8113" length="4140" />
    </pages>
  </query>
</api>