It's window.name-based transport for jQuery.Ajax with crossdomain file's uploading support
$.ajax(
'http://your-upload-url/',
{
files : $('input[type=file]'),
dataType : 'json',
success : function(data) {
// files loaded
},
// another usual ajax options
});
On success response must put answer in window.name as json. Response's example:
<script type="text/javascript">window.name='{"status":"ok","size":1024}';</script>