I'm an admin on the Clojurians Slack workspace where we have about 15,000 members, of whom about 1,400 or so are considered "active" for Slack's purpose -- whic

I'm an admin on the Clojurians Slack workspace where we have about 15,000 members, of whom about 1,400 or so are considered "active" for Slack's purpose -- which is still an unaffordable amount for an open source community. Over the years since we created the Clojurians Slack, we've tried to create communities on a broad range of alternatives. None of the others have gained traction, unfortunately. I think Zulip is probably the best alternative and it offers a free option for open source projects with full history/searching, and that's probably been the most successful alternative so far. Clojure's community on IRC was in the hundreds. Slack very quickly became thousands. It surprised us. The fact that none of the alternatives have grown has also surprised us but people go where people go.