Riot : Riot allows teams to communicate across a wide range of collaboration apps. If some team members use Riot while others use IRC, Slack or Gitter, Riot ...
Zulip : Powerful slack-like open source group chat
Beehive : Beehive is an event and agent system, which allows you to create your own agents that perform automated tasks triggered by events and filters. It is m...
Mailtrain : Mailtrain is a self hosted newsletter application built on Node.js (v5+) and MySQL (v5.5+ or MariaDB). Mailtrain supports subscriber list management, ...
Lemmy : Lemmy is a selfhosted social link aggregation and discussion platform. It is completely free and open, and not controlled by any company. This means t...
Mattermost is a self-hosted solution for bringing all your team communication to one place, and making it searchable and accessible anywhere