messaging

A realtime distributed messaging platform

An elegant messages UI library for iOS

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

Apache Pulsar - distributed pub-sub messaging system

An Open-Source, Cloud-Native, Distributed MQTT Message Broker for IoT.

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

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

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

OpenIM: Instant messaging open source project based on go built by IM technology experts. Backend in Go.（由IM技术专家打造的基于 Go 实现的即时通讯（IM）项目，从服务端到客户端SDK开源即时通讯（IM）整体解决方案，可以轻松替代第三方IM云服务，打造具备聊天、社交功能的app。）

即时通讯(IM)系统

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

Scalable real-time messaging server in a language-agnostic way. Set up once and forever.

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

A community-driven replacement for JSQMessagesViewController

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

Distributed Application Framework for .NET

Open source, native iOS Messenger, with realtime chat conversations (full offline support).

Franz is a free messaging app for services like WhatsApp, Slack, Messenger and many more.

The most widely used PHP client for RabbitMQ

⚡️ A framework for building conversational user interfaces.

The most beautiful SMS messenger for Android

Anonymous peer-to-peer instant messaging

Android library. Flexible components for chat UI implementation with flexible possibilities for styling, customizing and data management. Made by Stfalcon

Apache Kafka® running on Kubernetes

ChatSecure is a free and open source encrypted chat client for iOS that supports OTR and OMEMO encryption over XMPP.

A 100% native C# implementation of ZeroMQ for .NET