In our office we are looking for a self-hosted / on-premises real-time communication tool, that ideally integrates with our other tools (tasks, wiki, code, review, …). A colleague would like a “desktop app” and I would prefer something that integrates into my desktop chat system (KDE Telepathy / XMPP).
Mattermost provides most of this, but does (afaik) not integrate with Phabricator directly. There was a feature request once, but nothing came out of it. There was an ancient project implementing a Phabricator/Slack bridge (Mattermost is afaik Slack compatible) and one that is actively maintained: Phabulous