Chat Open Source Tools

Alternative toSlack

Peer-to-peer serverless chat app with no central server

• 2,659 GitHub stars
• GPL-3.0Licence GPL-3.0
• #Chat

Alternative toDiscord

Free open source Discord reimplementation with full API parity

• 2,210 GitHub stars
• AGPL-3.0Licence AGPL-3.0
• #Chat

Alternative toDiscord

Self-hosted Discord-style chat with encrypted DMs and voice

• 645 GitHub stars
• AGPL-3.0Licence AGPL-3.0

Alternative toDiscord

Open source Discord alternative with flexible community tools

• 400 GitHub stars
• AGPL-3.0Licence AGPL-3.0
• #Chat

Alternative toSlack

Matrix team chat with a companion identity server

• 171 GitHub stars
• AGPL-3.0Licence AGPL-3.0
• #Chat

Alternative toWWhatsApp

Free P2P encrypted messaging, calls, and file sharing

• 168 GitHub stars
• GPL-3.0Licence GPL-3.0
• #Chat

Alternative toConductor

Desktop canvas for persistent multi-agent AI teams, Windows-only

• 168 GitHub stars
• MITLicence MIT
• #AI Agents

Alternative toSlack

Decentralized open source workplace with chat and docs

• 59 GitHub stars
• MPL-2.0Licence MPL-2.0
• #Chat

Alternative toSlack

Lightweight self-hosted messaging platform for teams

• 13 GitHub stars
• AGPL-3.0Licence AGPL-3.0
• #Chat