Discourse can be used a mailing list, discussion forum, and long-form chat room. It can be self-hosted for free, or hosted at discourse.org (or other providers) for a fee. It offers a clean interface and modern features, including email integration and notifications.
Discourse is a free, open-source, user-controlled alternative to discussion groups on Facebook and other social-media networks.
Class discussion forum
How to use it
- Comment threads on WordPress through integration
- Facebook Groups
- Older forum software