[reaperducer]

InVision lets you self-host when you're small, then move to its cloud when you grow:

https://invisioncommunity.com/

It's been around for decades, and allows your forum to be part of the real, open internet. Not locked behind some Discord or Facebook wall.

[Jsttan]

Just curious, I has noticed that it is only possible to host it on their cloud, and doesn't have any autonomy to host the forum myself?

[DrillShopper]

A link to this page is buried (nearly hidden) under all of their monthly cloud plans: https://invisioncommunity.com/buy/self-hosted/

So you can self host but they'd rather make recurring revenue from you.