Messaging GitHub Repositories (2026) · Open Source Tools

Macro is a unified workspace for teams: email, chat, docs, tasks, agents, calls, and CRM — @-linked together with shared AI memory.

ZapFast: a fast, native WhatsApp client in Rust and egui

bluetooth mesh chat, IRC vibes

Apache Iggy: Hyper-Efficient Message Streaming at Laser Speed

Scalable real-time messaging server in a language-agnostic way. Self-hosted alternative to Pubnub, Pusher, Ably, socket.io, Phoenix.PubSub, SignalR. Set up once and forever.

Efficient reliable UDP unicast, UDP multicast, and IPC message transport

Communication for AI agents: stable identity, durable mail and chat, and wake-up events across sessions, runtimes, machines, and organizations. MIT, self-hostable.

Self-hosted private chat: no cloud, no telemetry, no Big Tech. Discord alternative that runs on your own machine.

Native, pure C++, Slack client for Linux, macOS and Windows. Lightweight alternative to the official Electron app.

Real-time messaging library for Go. The simplest way to add feature-rich and scalable WebSocket support to your application. The core of Centrifugo server.

ZeroMQ core engine in C++, implements ZMTP/3.1

Apache Kafka® running on Kubernetes

Apache RocketMQ is a cloud native messaging and streaming platform, making it simple to build event-driven applications.

Keep passwords and other sensitive information out of your chat logs and inboxes.

Rust client for NATS, the cloud native messaging system.

Apache Artemis

Distributed Application Framework for .NET

🚀 Apache RocketMQ built in Rust 🦀 — faster, safer, and more memory-efficient. Powering high-performance messaging for the AI era, with AI Agent, MCP, and AI-SRE capabilities.

Pluggable foundation blocks for building distributed apps.

A lightweight SwiftUI chat UI framework with 11 built-in message types, 8 themes, and cross-platform iOS/macOS support