Team Chat & Collaboration
Open-source Slack, Discord, and Microsoft Teams alternatives — messaging and collaboration you host yourself.
Fully customizable open-source communications platform and Slack alternative
Open-source notification infrastructure for multi-channel developer alerts
Open-source, self-hostable Slack alternative for secure team messaging and collaboration
Simple HTTP-based push notifications to phone and desktop, no account needed
Self-hostable open-source video conferencing alternative to Teams meetings
Open-source team chat with a unique topic-based threading model
Python library and CLI to send notifications to 70+ services via one unified API
Self-hosted push notification server with Android app and REST API
Open-source instant messaging server with a Go backend and multi-platform clients
Matrix-based secure messenger and Slack alternative with end-to-end encryption
The most private chat platform — no user IDs, double ratchet E2E encryption
Browser-based screen sharing for one or many viewers using WebRTC
Language-agnostic real-time messaging server over WebSocket and SSE
Drag-and-drop conversational form builder embeddable in any website or app
Low-latency, high-quality open-source voice and text chat for gaming and teams
Modern, self-hosted web IRC client for always-on team chat
Virtual office and conference as an interactive 16-bit RPG world in the browser
Reference Matrix homeserver powering decentralized, federated team chat
Fast, extensible terminal IRC and chat client with a rich plugin ecosystem
Modern IRCv3 server in Go combining ircd, services framework, and bouncer
Share sensitive data via self-destructing links viewable only once
Distributed, serverless messenger with encrypted audio and video calls
Real-time collaborative whiteboard for drawings, diagrams, and notes
User-first self-hosted team chat platform built with Rust
High-performance realtime server for WebSockets and Server-Sent Events
Serverless peer-to-peer ephemeral chat with no accounts required
Open-source, Discord-compatible chat backend you can self-host
Self-hosted chat, video calls, and conferencing integrated into Nextcloud