http://www.inf.ethz.ch/department/IS/ea/blinds/ http://muffin.doit.org/ http://freshmeat.net/projects/webcleaner/?topic_id=90%2C907 http://www.delorie.com/web/purify.html http://www.cus.cam.ac.uk/~ssb22/help.htm http://www.vorburger.ch/projects/alt/