A realtime distributed messaging platform

• UpdatedJul 13, 2025
• Go

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

• UpdatedFeb 13, 2026
• Java

High-Performance server for NATS.io, the cloud and edge native messaging system.

• UpdatedFeb 20, 2026
• Go

The most scalable and reliable MQTT broker for AI, IoT, IIoT and connected vehicles

• UpdatedFeb 20, 2026
• Erlang

IM Chat ChatGPT

• UpdatedFeb 9, 2026
• Go

Apache Pulsar - distributed pub-sub messaging system

• UpdatedFeb 20, 2026
• Java

Open source RabbitMQ: core server and tier 1 (built-in) plugins

• UpdatedFeb 20, 2026
• JavaScript

Instant messaging platform. Backend in Go. Clients: Swift iOS, Java Android, JS webapp, scriptable command line; chatbots

• UpdatedFeb 20, 2026
• Go

An elegant messages UI library for iOS

• UpdatedDec 12, 2018
• Objective-C

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

• UpdatedJan 23, 2026
• C++

SimpleX - the first messaging network operating without user identifiers of any kind - 100% private by design! iOS, Android and desktop apps 📱!

• UpdatedFeb 20, 2026
• Haskell

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.

• UpdatedFeb 19, 2026
• Go

Berty is a secure peer-to-peer messaging app that works with or without internet access, cellular data or trust in the network

• UpdatedFeb 20, 2026
• TypeScript

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

• UpdatedFeb 19, 2026
• Java

Distributed Application Framework for .NET

• UpdatedFeb 7, 2026
• C#

Robust, Ubiquitous and Massively Scalable Messaging Platform (XMPP, MQTT, SIP Server)

• UpdatedFeb 20, 2026
• Erlang

A community-driven replacement for JSQMessagesViewController

• UpdatedFeb 12, 2026
• Swift

Apache Kafka® running on Kubernetes

• UpdatedFeb 20, 2026
• Java

Kafka implemented in Golang with built-in coordination (No ZK dep, single binary install, Cloud Native)

• UpdatedNov 13, 2023
• Go

qTox is a chat, voice, video, and file transfer IM client using the encrypted peer-to-peer Tox protocol.

• UpdatedFeb 16, 2025
• C++