Review on Discourse by Eric Williamson

I like that it's easy to set up, has great documentation for new users, and allows me to have multiple forums in one place (with different rules).

It also lets you use your own domain if you want. There are some things about discourse which don't feel as intuitive or polished compared with other platforms such as Slack - but this could be because of my lack of experience using them! You can easily create custom fields so people who join an organisation get assigned certain roles automatically without having to manually add each person into those groups. This makes onboarding much easier than before.