Question

This is returning an XML file and normal .get is not allowed, what am I doing wrong?
Here’s their guide: http://svc.metrotransit.org/NexTrip/help/operations/GetRoutes

jQuery(document).ready(function($) { 
 var url = "http://svc.metrotransit.org/NexTrip/Routes?callback=?";
  $.getJSON(url, function (data) {
            $('#content').append(data);
  });    
});

Answer 1

You need to explicitly request the response format to be JSON, by adding format=json to the query string:

jQuery(document).ready(function($) { 
  var url = "http://svc.metrotransit.org/NexTrip/Routes?format=json&callback=?";
  $.getJSON(url, function (data) {
    for (var i = 0; i < data.length; i++) {
      $("#content").append(data[i].Description + "<br />");
    }
  });    
});

DEMO.