Rocket.Chat
Communications platform that puts data protection first (alternative to Gitter.im and Slack).
Self-hosted Communication - Custom Communication Systems software
Communication software used to provide remote access to systems and exchange files and messages in text, audio and/or video formats between different computers or users, using their own custom protocols.
46 apps, ranked by GitHub stars weighted by maintenance health.
Novu
Notification infrastructure for developers.
Mattermost
Platform for secure collaboration across the entire software development lifecycle, can be integrated with Gitlab (alternative to Slack).
Chatwoot
Customer communication platform (alternative to Intercom and Zendesk).
ntfy
Push notifications to phone or desktop using HTTP PUT/POST, with Android app, CLI and web app, similar to Pushover and Gotify.
Zulip
Powerful group chat application.
SimpleX Chat
Most private and secure chat and applications platform - now with double ratchet E2E encryption.
Apprise
Apprise allows you to send a notification to almost all of the most popular notification services available to us today such as: Telegram, Discord, Slack, Amazon SNS, Gotify, etc.
OpenWA
WhatsApp API gateway exposing messaging as REST endpoints, with a web dashboard, multi-account sessions, and webhook events (alternative to WhatsApp Business API providers).
Gotify
Notification server with Android and CLI clients (alternative to PushBullet).
Element
Fully-featured Matrix client for Web, iOS & Android.
Tinode
Instant messaging platform. Backend in Go. Clients: Swift iOS, Java Android, JS webapp, scriptable command line; chatbots.
Centrifugo
Language-agnostic real-time messaging (Websocket or SockJS) server.
Fluxer
Instant messaging and VoIP platform built for friends, groups, and communities (alternative to Discord).
Screego
Simple tool to quickly share your screen to one or multiple people via web browser.
Typebot
Conversational app builder (alternative to Typeform and Landbot).
Mumble
Low-latency, high quality voice/text chat software.
WorkAdventure
Virtual office / virtual conference application presented as a 16-bit RPG video game.
Synapse
Server for Matrix, an open standard for decentralized persistent communication.
One Time Secret
Share sensitive information securely with self-destructing links that are only viewable once.
Tuwunel
High-performance and feature-rich chat server for Matrix, and the successor to conduwuit (fork of Conduit).
Stoat
User-first chat platform built with modern web technologies.
WBO
Web Whiteboard to collaborate in real-time on schemas, drawings, and notes.
AnyCable
Realtime server for reliable two-way communication over WebSockets, Server-sent events, etc.
Chitchatter
Peer-to-peer chat app that is serverless, decentralized, and ephemeral.
Live Helper Chat
Live Support chat for your website.
GlobaLeaks
Whistleblowing software enabling anyone to easily set up and maintain a secure reporting platform.
Hyphanet
Anonymously share files, browse and publish freesites (web sites accessible only through Hyphanet) and chat on forums.
Conduit
Simple, fast, and reliable chat server powered by Matrix.
OTS
One-Time-Secret sharing platform with a symmetric 256bit AES encryption in the browser.
Tox
Distributed, secure messenger with audio and video chat capabilities.
RetroShare
Secured and decentralized communication system. Offers decentralized chat, forums, messaging, file transfer.
Shhh
Keep secrets out of emails or chat logs, share them using secure links with passphrase and expiration dates.
Databag
Federated, end-to-end encrypted messaging service for the web, iOS, and Android, supporting text, photos, video, and WebRTC video and audio calls.
Notifo
Multichannel notification server with support for Email, Mobile Push, Web Push, SMS, messaging and a javascript plugin.
SAMA
Next-Gen self-hosted chat server and clients.
Spectrum 2
Instant messaging transport. It allows users to chat together even when they are using different IM networks.
PushBits
Notification server for relaying push notifications via Matrix, similar to PushBullet and Gotify.
Tiledesk
All-in-one customer engagement platform from lead-gen to post-sales, from WhatsApp to your website. With omni-channel live agents and AI-powered chatbots (alternative to Intercom, Zendesk, Tawk.to).
Continuwuity
Community-driven Matrix homeserver, the continuation of conduwuit focusing on user experience and new features (fork of Conduit).
GNUnet
Software framework for decentralized, peer-to-peer networking.
Groupboard
Online whiteboard, audio/video conferencing, screen sharing, shared code editing and optional session recording/playback.
Jami
Universal communication platform which preserves the user's privacy and freedoms.
PrivMX WebMail
Web-based, end-to-end encrypted email platform that uses an independent PKI.
TrueConf
Platform for your corporate communications, based on the advanced architecture, with support for UltraHD video conferencing, built-in messenger with personal and group chats, and a free version for up to 1,000 users.
Virola Messenger
Instant messaging and collaboration tool with private and group chat rooms, continuous voice and video meetings, files sharing, issue tracking with integrated task board (alternative to Slack).