QBO3 is built with MooTools, and does not rely on jQuery in any way.
That said, jQuery is available for use in creating custom behaviors.
In QBO3, jQuery is operating in noConflict mode, so the '$' designation is not available.
A typical jQuery operation would use the '$' in this fashion:
$('#results')
In QBO3, one must use the 'jQuery' designation instead, like this:
jQuery('#results')