Here are the top five popular (free self hosted) commenting systems:

1- Commento: Commento is a lightweight, privacy-focused commenting system that can be self-hosted for free. It offers features such as moderation, spam filtering, and custom theming. The source code is available on GitHub under the MIT license.

2- Isso: Isso is a fast and lightweight commenting server that can be self-hosted for free. It offers features such as moderation, spam filtering, and user authentication. The source code is available on GitHub under the MIT license.

3- HashOver: HashOver is a self-hosted commenting system that can be used as an alternative to Disqus. It is lightweight and easy to install, and offers features such as moderation and spam filtering. The source code is available on GitHub under the GNU General Public License.

4- Juvia: Juvia is a self-hosted commenting system that is free for personal and non-commercial use. It offers features such as moderation, spam filtering, and custom theming. The source code is available on GitHub under the MIT license.

5- Talkyard: Talkyard is an all-in-one community platform that includes a commenting system. It can be self-hosted for free and offers features such as real-time updates, moderation, and user profiles. The source code is available on GitHub under the Apache License, Version 2.0.

Discourse vs. Isso:

Commento and Isso are both self-hosted, free commenting systems that offer similar features such as moderation, spam filtering, and user authentication. However, there are some differences between the two:

  • Commento is more focused on privacy and security. It offers features such as anonymous commenting and no tracking, which may be important for some users. Isso, on the other hand, does not have these privacy-focused features.

  • Isso is written in Python, while Commento is written in Go. This may be important for users who prefer one programming language over the other or have experience working with one of the languages.

  • Commento offers more customization options, including custom theming, custom domains, and custom URLs. Isso does not offer these customization options out of the box.

  • Commento has a user-friendly interface that is easy to use and navigate. Isso has a more minimalistic interface that may be less intuitive for some users.

Overall, the choice between Commento and Isso will depend on the specific needs and preferences of the user. If privacy and customization are important factors, Commento may be the better choice. If simplicity and ease of use are more important, Isso may be the better choice.