I don\'t get what jQuery(document) is here. I thought you always used $(document)
see here in his examples: http://sorgalla.com/projects/jcarousel/
jQuery uses $(). Prototype uses $(). AFAIK Mootools uses $(). If that was the end of it, it would be impossible to use any combination of the three. So responsible frameworks provide a way to disable $() to avoid conflicts and use something else instead. In jQuery's case, that's jQuery().
jQuery() is recommended over $() for use in jQuery plugins, so they keep functioning if you do disable $().