I can\'t figure out how to listen to focus, click, onKeyUp and other basic dom events in ckeditor. In the events summary there is only a few events regarding the lifecycle o
CKEditor actually has built-in event handling in the object. See this article for an explanation: http://alfonsoml.blogspot.com/2009/09/ckeditor-events.html
So, to catch a modification in a CKEditor instance you could do this:
CKEDITOR.on('currentInstance', function(){modified = true;});
Also, it appears that version 3 has an event processor built into it that's more straightforward: http://docs.cksource.com/ckeditor_api/symbols/CKEDITOR.ui.dialog.file.html#eventProcessors
CK is a bit convoluted and documentation has holes, but based on its ability to gracefully handle Word generated HTML it gets my vote as the best option out there.