I don't plan to go on and on publishing url's of company's (wich are free advertisement, wich is rather biased and a bad habit of mine) but since there seemed to be some demand for securing/auditing the linux environment here it is http://www.tripwire.org It is an open source version of commercial software. [ to make up for the .com's :-) ] I hope it is of any use to someone. greetings, Joris