4 ms·

Mattermost is open core. Seems zulip might be as well, but the open source version seems more featureful

• tabbott 9y ago
  Zulip is 100% open source; we're not playing the "open core" game that Mattermost is.
• rishig 9y ago
  Zulip is fully FOSS. The project makes money from hosting and enterprise support.