FREE TRIALShttps://www.quetext.com/pricing]
&MOODLE plugins
https://unicheck.com/
https://plagiarismsearch.com/
FLOSS
https://www.reddit.com/r/opensource/comments/8xgldr/any_freeopensource_software_for_plagiarism/https://github.com/architshukla/Plagiarism-Checker