List of free comment stuff for developerππ½
If you're looking for all programming tools around comment (not just free). Check this page List of comment Programming Tools

Commentbox
Hosted commenting that's painless to embed, a pleasure to use, and a breeze to moderate
Tag: comment
1GB bandwidth monthly 100 comments monthly


Cactus Comments
Cactus Comments is a federated comment system for the web, based on the Matrix protocol.
Tag: comment
Hashover
A free and open source PHP comment system designed to allow completely anonymous comments and easy theming
Tag: comment

Disqus
Disqus offers the best add-on tools for websites to increase engagement. We help publishers power online discussions with comments and earn revenue with native advertising
Tag: comment
Real time comments Automated Spam Moderation
Commentics
Commentics is a free, advanced PHP comment script with many features. Professionally written and with open source code, its main aims are to be integrable, customizable and secure. It is designed to be integrated into existing pages.
Tag: comment
Display the “Powered By” Forum Support

Webmention.io
Webmention.io is a hosted service created to easily receive webmentions on any web page.
Tag: comment, webmention
Free self-hosted