Easy Comments is a straight forward free PHP comment script to add simple inline comments to your pages. Comments are stored in a flat ASCII (mark-up enhanced) file. Hence, no database is required.
Review the complete sources and download a free copy from the GitHub repository.
Basic help and support is available via E-mail. Updates are usually announced in the News section.
Follow this link to register and receive automatic update notifications. Registration is optional and free with no strings attached.