Self-hosted Communication & Collaboration tools

Open-source, privacy-focused collaborative workspace for notes, databases, kanban boards and AI-assisted writing; desktop, mobile and web clients with local-first storage.

AGPL-3.0Actively maintained

Alternative to:

Notion+19

All-in-one, privacy-focused workspace that merges docs, whiteboards and databases with real-time collaboration and multimodal AI assistance.

Actively maintained

Alternative to:

Notion+16

Rocket.Chat is an open-source communications platform for secure team messaging, channels, DMs, voice/video, integrations, and customer omnichannel support.

Actively maintained

Alternative to:

Rocket.Chat Cloud+19

Novu is an open-source notifications platform with a unified API, workflow orchestration, and embeddable in-app inbox for email, SMS, push, and chat.

Actively maintained

Alternative to:

Novu Cloud+4

Open-source, self-hosted messaging platform for secure team collaboration with real-time chat, audio calls, screen sharing, and integrations.

Actively maintained

Alternative to:

Slack+19

Nextcloud is an open-source content collaboration platform providing file sync & share, groupware (calendar, contacts, mail), real-time office editing, chat and video conferencing.

AGPL-3.0Actively maintained

Alternative to:

Google Drive+19

Chatwoot is an open-source customer support platform with a shared inbox for live chat, email, and messaging channels, plus automation, reporting, and a help center.

Actively maintained

Alternative to:

Intercom+19

ntfy is a lightweight HTTP pub-sub service to send push notifications to phones, desktops, and browsers via PUT/POST or a REST API.

Apache-2.0Actively maintained

Alternative to:

Pushover+8

Self-hostable WebRTC video conferencing with chat, screen sharing, moderation tools, and SDKs for embedding meetings into web and mobile apps.

Apache-2.0Actively maintained

Alternative to:

Zoom+12

SRS (Simple Realtime Server) is a high-efficiency media server supporting RTMP, WebRTC, HLS, HTTP-FLV, SRT, MPEG-DASH, and GB28181 for real-time streaming.

MITActively maintained

Alternative to:

Wowza Streaming Cloud+8

Huly is an open-source all-in-one platform combining project management, team chat, and collaborative documentation as an alternative to tools like Jira, Linear, Slack, and Notion.

EPL-2.0Actively maintained

Alternative to:

Linear+19

Open-source team chat server with topic-based threading for focused, asynchronous, and real-time communication in distributed teams.

Apache-2.0Actively maintained

Alternative to:

Zulip Cloud+19

Open-source, decentralized messaging network built on a Haskell core with Kotlin Multiplatform and native iOS clients; end-to-end encrypted messaging without user IDs.

AGPL-3.0Actively maintained

Alternative to:

Signal+11

Production-ready mail server stack in a Docker container with SMTP, IMAP/POP3, LDAP auth, anti-spam/AV, DKIM/DMARC, and optional OAuth2 support.

MITActively maintained

Alternative to:

Gmail+16

Etherpad is a web-based real-time collaborative editor with chat, rich-text formatting, and a plugin framework for customization and integrations.

Apache-2.0Actively maintained

Alternative to:

Etherpad Cloud+9

Open-source, web-based LaTeX editor for real-time collaboration, project management, and PDF compilation in the browser.

AGPL-3.0Actively maintained

Alternative to:

Overleaf

Postal is an open source mail delivery platform for sending and receiving email, with SMTP support, web-based management, and tools for running your own SendGrid-style service.

MITActively maintained

Alternative to:

SendGrid+10

Gotify is a self-hosted notification server that delivers messages in real time via WebSocket, with a REST API, web UI, and optional clients like Android and CLI.

Mail-in-a-Box is a one-click mail server appliance for Ubuntu, bundling SMTP/IMAP, webmail, DNS, TLS automation, backups, and an admin control panel.

CC0-1.0Actively maintained

Alternative to:

Microsoft Exchange Online+15

Habitica is an open-source gamified task manager turning Habits, Dailies, and To-Dos into RPG quests with avatars, gear and social features.

Actively maintained

Alternative to:

Habitica+15

All-in-one open-source mail and collaboration server with SMTP, IMAP, JMAP, CalDAV, CardDAV, and WebDAV, plus integrated anti-spam and phishing protection.

Actively maintained

Alternative to:

Microsoft Exchange Online+19

Tinode is an open source instant messaging platform with a Go backend, web/mobile clients, JSON WebSocket and gRPC APIs, and support for one-to-one and group chat.

GPL-3.0Actively maintained

Alternative to:

Telegram+13

Element is a Matrix client for secure team messaging and collaboration, offering end-to-end encrypted chats and calls with interoperability across the Matrix network.

AGPL-3.0Actively maintained

Alternative to:

Element Matrix (Hosted)+19

Mailcow is a dockerized mail server suite providing SMTP/IMAP, webmail, anti-spam/anti-virus, and domain/mailbox administration via a unified web UI.

GPL-3.0Actively maintained

Alternative to:

Microsoft Exchange Online+16

Owncast is a self-hosted live streaming server that supports RTMP ingest, HLS playback, and built-in web chat, with optional Fediverse (ActivityPub) integration.

MITActively maintained

Alternative to:

YouTube+12

Open-source screen sharing server that runs self-hosted; WebRTC-based with TURN server; Docker or single-binary deployment; browser-based.

GPL-3.0Actively maintained

Alternative to:

Zoom+11

BigBlueButton is an open-source virtual classroom and web conferencing platform with real-time audio/video, screen sharing, whiteboards, breakout rooms, polling, and recordings.

LGPL-3.0Actively maintained

Alternative to:

Zoom+14

Janus WebRTC Server is a lightweight, general-purpose WebRTC gateway for building real-time audio/video applications via plugins and a JSON-based API.

GPL-3.0Actively maintained

Alternative to:

Ant Media Server Cloud+2

Open-source platform for secure file sync, sharing, collaboration, calendars and external storage with WebDAV/CalDAV/CardDAV support.

AGPL-3.0Actively maintained

Alternative to:

Dropbox+19

Mumble is an open-source, low-latency VoIP voice chat platform with a desktop client and a self-hosted server for encrypted group communication.

Actively maintained

Alternative to:

Skype+4