Discourse (https://www.discourse.org/ https://www.discourse.org/) seems to be used very frequently, at least for open source projects. EDIT: forgot to mention

Discourse (https://www.discourse.org/ https://www.discourse.org/) seems to be used very frequently, at least for open source projects. EDIT: forgot to mention that Discourse is self-hostable, if that's your thing: https://github.com/discourse/discourse/blob/main/docs/INSTALL.md https://github.com/discourse/discourse/blob/main/docs/INSTAL...