ESR's released a tool based on the shred algorithmn : http://www.catb.org/~esr/comparator/ has an article about it at Eweek, http://www.eweek.com/article2/0,4149,1257617,00.asp. Anyone who just happens to have access to commercial source, can ensure developers haven't cut corners and borrowed from GPL or broken the Berkeley Copyright clause :) Rob