ProWritingAid - For the smarter writer. A grammar checker, style editor, and writing mentor in one package.

iThenticate - Prevent Plagiarism in Published Works

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.

Keygen - A dead-simple software licensing API built for developers

PlagScan - The Internet makes plagiarism a bigger problem than ever.

Unicheck - The plagiarism checker Unplag scans across the internet, repositories, open sources content and databases. It delivers real-time results and has no cached data.