As Doug Crockford created JSON it became something of an antidote to XML. This was bound to happen, because the issues developers had with XML were so plentiful. JSON, of course, with an API that fit on a business card, was more than a counter-statement. It was a big success in the making. Twitter recently dropped XML from its API, and this caused a few ripples in the XML/JSON blogosphere. Check this bit on XML versus the Web from Ajaxian.