http://www.citationmachine.net/ Citation Machine helps students and professional researchers to properly credit the information that they use. Its primary goal is to make it so easy for student researchers to cite their information sources, that there is virtually no reason not to.
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.