For MapBuzz browser testing, we need to control the x and y locations of the
mouse cursor. Selenium didn’t support this functionality, so I coded it up one evening and submitted a patch.

Nelson Sproul took the patch, refactored it a bit, and included it in the
recent 0.7.1 Selenium release. Note that there is a major limitation when using
it with Internet Explorer. IE does not bubble script generated events. Thus,
if you send a mouseclick event to an element, it will receive it, but will
not bubble it up to its parent in the DOM tree.