Mattermost is also open source, (AGPLv3 with lots of components optionally available via MIT or Apache terms). It does require contributors to sign a CLA though (unlike Zulip as far as I can tell?), and this likely reduces community involvement.
Mattermost has threads, though they work different from Zulip.
I haven't used both extensively, and for an open community like Hack Club, I suppose it's possible Zulip may even be a better fit. Mattermost will offer a much more direct migration path from Slack however.
I'm curious what makes some recommend Zulip so highly over Mattermost.
Mattermost has threads, though they work different from Zulip.
I haven't used both extensively, and for an open community like Hack Club, I suppose it's possible Zulip may even be a better fit. Mattermost will offer a much more direct migration path from Slack however.
I'm curious what makes some recommend Zulip so highly over Mattermost.