Maybe searching for "plagiarism detection" or "finding similarities" on the internet could show some usefull software. Besides the one mentioned by Mike Castle, of this type is, e.g., JPlag http://wwwipd.ira.uka.de:2222/. Here are also some sources listed: Plagiarism detection - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Plagiarism_detection -- Regards, Jörg-Volker.