Talkyard - Forum software, brings together the best from StackOverflow, Discourse, Slack, Reddit, Disqus

•    Scala

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Talkyard is a Forum software, brings together the best from StackOverflow, Discourse, Slack etc. It helps people find help "instantly", in Question & Answers topics, Discuss, upvote and choose the right things to do. It also provides support to do team chat, Add embedded comments to the blog.

forum stackoverflow-like question-answer qa comments commenting-system commenting-engine slack-alternative

RocketChat - The ultimate open source web chat platform

•    Coffeescript

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Rocket.Chat is a Web Chat Server, developed in JavaScript, using the Meteor fullstack framework. It is a great solution for communities and companies wanting to privately host their own chat service or for developers looking forward to build and evolve their own chat platforms. Its features include File sharing, Video conferencing, Screen sharing, Live chat, Link preview and lot more.

chat chat-server screen-sharing video-conference slack-alternative webchat instant-messaging im secure-messaging

Gitter - Community for Software Developers

•    Javascript

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Gitter is designed to make community messaging, collaboration and discovery as smooth and simple as possible. You can easily create, organise and grow your communities, inviting others to join just in one click. Gitter is an instant messaging and chat room system for developers and users of GitHub repositories. Gitter is similar to IRC and Slack. Unlike IRC, and like Slack, it automatically logs all messages in the cloud.

chat instant-messaging im slack-alternative secure-chat

Mattermost - Self-hosted Team Communication Service

•    Go

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Mattermost is self-hosted team communication service bringing messaging and file sharing into one place, accessible across PCs and phones, with archiving and search.

chat chat-server slack-alternative collaboration communication messaging

Zulip - Group Chat

•    Python

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Zulip is a powerful, open source group chat application. It supports both private messaging and group chats via conversation streams. Zulip also supports fast search, drag-and-drop file uploads, image previews, group private messages, audible notifications, missed-message emails, desktop apps, and much more.

chat im instant-messaging group-chat collaboration slack-alternative

Matrix - Decentralized group communication

•    Python

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Matrix is an open standard for decentralised communication, providing simple HTTP APIs and open source reference implementations for securely distributing and persisting JSON over an open federation of servers. It can be used for Decentralised Group Chat, WebRTC signalling, Internet of Things, VOIP etc.

voip webrtc skype-alternative video-conference slack-alternative instant-messaging chat

Element - Secure and independent communication, connected via Matrix

•    Java

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Element is a messaging app that lets you chat securely with your family and friends. The communication is default end-to-end encrypted, cross-signed device verification and decentralisation to choose who you trust with your data. Element is unique. You own your data and decide where it lives. Element lets you talk securely to anyone, regardless of their app. It supports unlimited voice, video and messaging. It is built on Matrix.

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Lets-Chat - Self-hosted chat for small teams

•    Javascript

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Let's Chat is a persistent messaging application that runs on Node.js and MongoDB. It's designed to be easily deployable and fits well with small, intimate teams. It supports XMPP Multi-user chat (MUC), Multiple rooms, File uploads and lot more.

chat instant-messaging messaging im xmpp self-hosted slack-alternative

braid - Braid is a team-chat app with a novel UI that leads to better conversations.

•    Clojure

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Braid is an experimental team chat application with a novel UI: instead of chatrooms, it's based on many short conversations. You can think of Braid as an email/mailing-list/web-forum/chatroom hybrid, but without the constant interruptions and FOMO of Slack. It's particularly good for remote-first companies, developer teams and online communities. Braid is also open-source, so you can hack on it and host your own version. You can read more about Braid and then give Braid a try.

chat instant-messaging slack-alternative group-chat team-chat

Friends - P2P chat powered by the web

•    Javascript

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Friends is like Slack except P2P, offline friendly and open source. Data is transmitted over secure channels and messages are authenticated. It is made by a group of open source developers who are motivated to make a public chat platform that is easy to use but isn't centrally controlled, and where data is owned by its users.

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