Open source instant-messaging projects
Every project in the registry tagged instant-messaging, ranked by real GitHub adoption.
Instant messaging platform. Backend in Go. Clients: Swift iOS, Java Android, JS webapp, scriptable command line; chatbots
Movim - Decentralized social platform
⚡ The future of programmable SIP servers.
Decentralized private messenger with chat-shared tools and games for Desktop
A modern, self-hosted team chat built on Cloudflare — realtime messaging, Telegram bridge, encrypted messages & files, and WebMCP. | 基于 Cloudflare 的现代自部署团队聊天系统：
🐙 The Go backend powering OCTO — an open workplace built for humans × AI agents. REST & WebSocket APIs, Lobster (AI agent) orchestration, and WuKongIM real-tim
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Frequently asked questions
How many open source instant-messaging projects are there?
This registry tracks 6 projects tagged instant-messaging, with 21,468 GitHub stars between them. The most-adopted is chat at 13,547 stars.
Are these instant-messaging projects free to use?
Yes — 6 of the 6 carry an explicit open-source licence across 4 distinct licences, so there is no licence fee. Where a project also sells a hosted or enterprise version, the self-hosted path remains free.
Which instant-messaging project should I choose?
The list above is ranked by GitHub stars, but stars measure attention rather than fit. Check three things on each card: the licence (permissive versus copyleft), the language it is written in, and the last-push date — a high-star project that has not been pushed in a year is a liability.
Are these instant-messaging projects still maintained?
6 of the 6 were pushed in the last 90 days, and every card shows its exact last-push date so you can see the rest. Sort your shortlist by that date before committing to a migration.