http://www.plagiarism.org/ Plagiarism.org is a free resource sponsored by iParadigms LLC, makers of Turnitin, WriteCheck, and iThenticate.
http://www.copygator.com/ This is a free service designed to monitor your RSS feed and find where your content has been republished in the blogosphere. We automatically notify you when a new post of yours is copied to another feed, we also build an overview page you can view to see how/when/where your content is being duplicated,…
https://www.doccop.com/index.html DOC Cop is a collusion, cryptomnesia and plagiarism detection tool. DOC Cop creates reports displaying the correlation and matches between documents or a document and the Web.
http://plagiarisma.net/ Free Online Plagiarism Checker for Students, Teachers, Scholars, Educators, Scientists, Essayists, Writers. Free Turnitin and Copyscape Alternative.
http://www.dustball.com/cs/plagiarism.checker/ This free plagiarism detector will find plagiarized text in homework and other essays/reports.