There is a 3rd alternative...
Atolia, the one and only workspace your team needs
Atolia is a power-packed all-in-one digital workplace: Chat, Video calls, Tasks & Projects, Calendars, Documents, Notes...
Accelerate your team's collaboration game.
Implement it in minutes and save money. Atolia is cheaper than most of the business instant messaging apps.
Why choose Mattermost or Zulip?
In terms of features, Zulip has some unique offerings such as workspace and user activity, whiteboarding, recording, participant permissions, and branding removal, while Mattermost offers support add-ons and custom domain names. Zulip also has better help resources with training, webinars, and a dedicated CSM, while Mattermost only offers a help center. Ultimately, the choice between the two would depend on specific needs and budget constraints.