Turnitin
Turnitin is a closed-source plagiarism detection service that promotes academic integrity, streamlines grading and feedback, deters plagiarism, and improves student outcomes.
Turnitin provides a web-based plagiarism detection service, which can be used as a deterrent and as a tool to teach students how to work with sources. Turnitin Feedback Studio also includes tools for peer review, automated spelling and grammar review, document annotation and feedback, and grading of student submissions.