GitHub stars · StarDay

1permissionlesstech / bitchatbluetooth mesh chat, IRC vibesSwiftUnlicense · Permissive37,081

2nsqio / nsqA realtime distributed messaging platformGoMIT · Permissive25,774

3apache / rocketmqApache RocketMQ is a cloud native messaging and streaming platform, making it simple to build event-driven applications.JavaApache-2.0 · Permissive22,654

4nats-io / nats-serverHigh-Performance server for NATS.io, the cloud and edge native messaging system.GoApache-2.0 · Permissive21,002

5simplex-chat / simplex-chatAuthor description: SimpleX - the first messaging network operating without user identifiers of any kind - 100% private by design! iOS, Android and desktop apps 📱!HaskellAGPL-3.0 · Share derivative source19,650

6emqx / emqxThe most scalable and reliable MQTT broker for AI, IoT, IIoT and connected vehiclesErlangLicense not declared16,887

7openimsdk / open-im-serverIM Chat OpenClawGoApache-2.0 · Permissive16,756

8apache / pulsarApache Pulsar - distributed pub-sub messaging systemJavaApache-2.0 · Permissive15,356

9rabbitmq / rabbitmq-serverOpen source RabbitMQ: core server and tier 1 (built-in) pluginsJavaScriptLicense not declared13,955

10tinode / chatInstant messaging platform. Backend in Go. Clients: Swift iOS, Java Android, JS webapp, scriptable command line; chatbotsGoGPL-3.0 · Share derivative source13,555

11eclipse-mosquitto / mosquittoEclipse Mosquitto - An open source MQTT brokerCLicense not declared11,342

12zeromq / libzmqZeroMQ core engine in C++, implements ZMTP/3.1C++MPL-2.0 · Share derivative source11,051

13centrifugal / centrifugoScalable 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.GoApache-2.0 · Permissive10,950

14berty / bertyBerty is a secure peer-to-peer messaging app that works with or without internet access, cellular data or trust in the networkTypeScriptLicense not declared9,344

15aeron-io / aeronEfficient reliable UDP unicast, UDP multicast, and IPC message transportJavaApache-2.0 · Permissive8,952

16MassTransit / MassTransitDistributed Application Framework for .NETC#Apache-2.0 · Permissive7,812

17processone / ejabberdRobust, Ubiquitous and Massively Scalable Messaging Platform (XMPP, MQTT, SIP Server)ErlangLicense not declared6,750

18MessageKit / MessageKitA community-driven replacement for JSQMessagesViewControllerSwiftMIT · Permissive6,271

19macro-inc / macroMacro is a unified workspace for teams: email, chat, docs, tasks, agents, calls, and CRM — @-linked together with shared AI memory.RustAGPL-3.0 · Share derivative source6,179

20strimzi / strimzi-kafka-operatorApache Kafka® running on KubernetesJavaApache-2.0 · Permissive5,972