Open source alternatives to Zoho Cliq

By GitHub stars it is Rocket.Chat, with 46,503 stars and a commit on 13 Nov. Choose Rocket.Chat when you need channels and threads you can federate with Matrix or XMPP partners and host yourself. Next come Mattermost (39,606 stars) and Buzz (37,297 stars).

Yes. The code of all 7 is public under MIT, AGPL 3.0, Apache 2.0 or GPL 3.0, so you can use them with no licence fee. Running one yourself costs the server and your time to look after it, and some makers also sell a hosted plan.

Start from the job you use Zoho Cliq for. Choose Buzz when you want to host it yourself and keep your data on your own server. Choose Mattermost when you need self-hosted team chat with incident playbooks and Jira, GitHub and GitLab hooks rather than a hosted Zoho workspace.

All 7: Rocket.Chat, Mattermost, Buzz, Campfire, Wire, Quiet and Twake Chat. Each tool's page says what it needs to run.

All 7 we track had a commit in the last 30 days, among them Rocket.Chat, Mattermost, Buzz and Campfire. A recent commit shows the project is kept up, not that it will stay that way.

AGPL 3.0 (3), MIT (2), Apache 2.0 (1), GPL 3.0 (1). MIT, BSD and Apache let you change and reuse the code freely. GPL and AGPL ask you to share your changes under the same licence when you give the software to others, and AGPL also counts letting people use it over a network.

The hosting. Zoho Cliq's maker runs the servers for you; with an open source tool the updates, backups, security fixes and support are yours, unless you take the maker's hosted plan. Features differ too, so check what each one imports and exports before you move your data.