List of Top Free Open Source & Self Hosted Application for Communication - Custom Communication Systems

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.

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. MIT Python/Docker
BluetoothCommunicatorExample – Bluetooth LE chat app to communicate between android devices with P2P architecture. Apache-2.0 Java
Centrifugo – Language-agnostic real-time messaging (Websocket or SockJS) server. (Demo, Source Code) MIT Go
Chatwoot – Self-hosted customer communication platform, an alternative to Intercom & Zendesk. MIT Ruby
Chitchatter – A peer-to-peer chat app that is serverless, decentralized, and ephemeral. GPL-2.0 Nodejs
Conduit – A simple, fast, and reliable chat server powered by Matrix. Apache-2.0 Rust
Darkwire.io – End-to-end encrypted instant web chat. MIT Nodejs
Databag – Federated, end-to-end encrypted messaging service for the web, iOS, and Android, supporting text, photos, video, and WebRTC video and audio calls. Apache-2.0 Docker
Dendrite – Second-generation Matrix homeserver written in Go. It intends to provide an efficient, reliable and scalable alternative to Synapse. Apache-2.0 Go
Element – Fully-featured Matrix client for Web, iOS & Android. Apache-2.0 Nodejs
Enigma Reloaded – DIY Message and file encryption for any platform. GPL-3.0 Javascript
Freenet – Anonymously share files, browse and publish freesites (web sites accessible only through Freenet) and chat on forums. GPL-2.0 Java
GNUnet – Free software framework for decentralized, peer-to-peer networking. GPL-3.0 C
Gotify – Self-hosted notification server with Android and CLI clients, similar to PushBullet. (Source Code, Clients) MIT Go
Hawkpost – HawkPost is a web app that lets you create unique links that you can share with a person that desires to send you important information but doesn’t know how to encrypt it. The message is encrypted in their browser and sent to your email address. MIT Python
Jam – Jam is an open source alternative to Clubhouse: private audio chat rooms to talk to friends and family. (Demo, Source Code) AGPL-3.0 Docker/Nodejs
Jami – Free and universal communication platform which preserves the user’s privacy and freedoms (formerly GNU Ring). GPL-3.0 C++
KChat – PHP Based Live Chat Application. Apache-2.0 PHP
LeapChat – Ephemeral, encrypted, in-browser chat rooms. AGPL-3.0 Docker/Nodejs/Shell
Live Helper Chat – Live Support chat for your website. Apache-2.0 PHP
Mattermost – Open-source, on-prem Slack-alternative. It can be integrated with Gitlab. AGPL-3.0/Apache-2.0 Go
MiAOU – Multi-room persistent chat server. MIT Nodejs
Mibew – Mibew Messenger is an open-source live support application written in PHP and MySQL. It enables one-on-one chat assistance in real-time directly from your website. (Demo, Source Code) Apache-2.0 PHP
Mumble – Low-latency, high quality voice/text chat software. (Source Code, Clients) BSD-3-Clause C++
Notifo – Multichannel notification server with support for Email, Mobile Push, Web Push, SMS, messaging and a javascript plugin. MIT C#
Novu – Self-hosted / cloud notification infrastructure for developers. MIT Docker/Nodejs
ntfy – Push notifications to phone or desktop using HTTP PUT/POST, with Android app, CLI and web app, similar to Pushover and Gotify. Apache-2.0/GPL-2.0 Go
OTS – One-Time-Secret sharing platform with a symmetric 256bit AES encryption in the browser. Apache-2.0 Go
Papercups – An open source live customer chat web app written in Elixir. (Demo, Source Code) MIT Elixir
PushBits – Self-hosted notification server for relaying push notifications via Matrix, similar to PushBullet and Gotify. ISC Go
Rallly – Rallly is an open-source alternative to Doodle that lets you create polls to vote on dates and times. AGPL-3.0 Nodejs
RetroShare – Secured and decentralized communication system. Offers decentralized chat, forums, messaging, file transfer. GPL-2.0 C++
Revolt – Revolt is a user-first chat platform built with modern web technologies. AGPL-3.0 Rust
Rocket.Chat – Teamchat solution similar to Gitter.im or Slack. MIT Nodejs
Screensy – Simple peer-to-peer screen sharing solution for sharing your screen with WebRTC. GPL-3.0 Nodejs
Shhh – Keep secrets out of emails or chat logs, share them using secure links with passphrase and expiration dates. MIT Python
SimpleX Chat – The most private and secure chat and applications platform – now with double ratchet E2E encryption. AGPL-3.0 Haskell
Soketi – Soketi is a free, open-source Pusher drop-in alternative. MIT Nodejs
Spectrum 2 – Spectrum 2 is an open source instant messaging transport. It allows users to chat together even when they are using different IM networks. GPL-3.0 C++
StoneAge Messenger – A self-hosted Android messenger, S3-compatible storage is the only backend needed. (Source Code, Clients) GPL-3.0 Java
Synapse – Server for Matrix, an open standard for decentralized persistent communication. Apache-2.0 Python
Syndie – Syndie is a libre system for operating distributed forums. CC0-1.0 Java
TextBelt ⚠ – Outgoing SMS API that uses carrier-specific gateways to deliver your text messages for free, and without ads. MIT Javascript
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. Self hosted alternative to Intercom, Zendesk, Tawk.to and Tidio. MIT Docker/K8S
Tinode – Instant messaging platform. Backend in Go. Clients: Swift iOS, Java Android, JS webapp, scriptable command line; chatbots. GPL-3.0 Go
Tox – Distributed, secure messenger with audio and video chat capabilities. GPL-3.0 C
Typebot – Typebot is a conversational app builder as an alternative to Typeform or Landbot. AGPL-3.0 Docker
WBO – Web Whiteboard to collaborate in real-time on schemas, drawings, and notes. AGPL-3.0 Nodejs/Docker
Yopass – Secure sharing of secrets, passwords and files. Apache-2.0 Go
Zulip – Zulip is a powerful, open source group chat application. Apache-2.0 Python