The forum software built by the people who walked out of vBulletin - and why, in an age of algorithmic feeds, businesses still pay for a place to talk.

Zapnito, Almabase, Disciple, XenForo, Gainsight and CMNTY are quietly selling brands a way to own their audience instead of renting it from a feed. Here is how one market splits into six very different bets.

Kajabi, Discourse, Disciple and a pack of rivals are selling creators and brands the same promise - leave the algorithm behind and own the people who show up. Here is who is actually fighting for the private community, and what they are betting on.