Mattermost is an open source, self-hosted Slack alternative.
tags: access-from-everywhere chat-rooms data-api go-lang group-chatMatrix.org is a growing ecosystem for open, decentralised chat, VoIP and IoT communication.
tags: chat-bot chat-clients communications decentralized distributedRocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework.
tags: ad-free channels chat-bot chat-rooms chat-serversOpensource task & productivity management tool for startups, engineered based on the concepts of OKR.
tags: project-management task-managementSelf-hosted chat for small teams.
tags: chat-clients chat-rooms chat-servers team-collaboration web-interfaceGitter is a chat and collaboration tool for developers and users. It's a place for developers to talk.
tags: chat-clients github messenger real-time-collaboration social-networkZulip is a group chat app.
tags: chat-servers github-integration group-chat group-collaboration integrated-file-sharingOinker looks like a plain chat program on the surface, but it allows you to save the specified messages (called ‘oinks’ in Oinker) on the spot, and more importantly, it allows you to connect the messages in an infinite number of ways to build sophisticated contents.
tags: chat-clients document-management document-sharing documentation ideashack.chat is a minimal, distraction-free chat application.Channels are created and joined by going to https://hack.chat/?your-channel . There are no channel lists, so a secret channel name can be used for private discussions.
tags: chat-clients chat-serversWhat does it do:
tags: Portable google-talk instant-messagingCampfire is a simple web-based real-time group chat tool for business. It makes real-time communication with 2-60 people as simple as visiting a web page.
tags: audio-conferencing business-chat chat-rooms decision-making group-chat