Turnitin - Turnitin is preferred by educational institutions around the world for preventing plagiarism. Instructors at all levels of education can request that students use the service to submit papers, and Turnitin checks those papers for plagiarism.
ProWritingAid - For the smarter writer. A grammar checker, style editor, and writing mentor in one package.
iThenticate - Prevent Plagiarism in Published Works
Plagramme - Our plagiarism checker recognizes paraphrased plagiarism, checks your paper against more that 14 trillion documents and lets you to edit your paper online.
Keygen - A dead-simple software licensing API built for developers
Urkund - Detect and check for plagiarism with URKUND