RabbitMQ vs ZeroMQ

RabbitMQ is an open source messaging and streaming broker for application communication, including distributed microservices, real-time data, and IoT. Publishers can route messages to one or more consumers using routing, filtering, streaming, and federation. Message acknowledgements and replication across a cluster support delivery reliability, and delivery guarantees are configurable. Supported protocols include AMQP 0-9-1, AMQP 1.0, MQTT, STOMP, RabbitMQ Streams, HTTP, and WebSocket, including browser communication over WebSocket. Client libraries are available for Java, .NET/C#, Erlang, and other languages; the project also offers a community Docker image and Kubernetes operators. RabbitMQ can run in cloud or on-premises environments, on local machines and physical or virtual hardware, and in containers. Linux, Windows, and macOS are supported; z/OS, most mainframes, and systems with less than 100 MB of RAM are not. The free, self-managed Open Source RabbitMQ Server is offered under the Mozilla Public License 2.0 with best-effort community support. VMware Tanzu RabbitMQ is a commercial offering with 24/7 support and enterprise features; pricing is by contact.

ZeroMQ is a free, open-source asynchronous messaging library for developers building distributed or concurrent applications. A system using it can run without a dedicated broker, with patterns such as publish-subscribe, request-reply and client-server. It carries messages over transports including TCP, in-process and inter-process communication, multicast and WebSocket. The project lists language bindings and libraries for C, C++, C#, Dart, Erlang, F#, Go, Haskell, Java, Node.js, Perl, Python, Ruby, Rust and Zig. Supported protocols also include ZMTP, UDP, IPC, PGM, NORM and TIPC, and delivery guarantees are configurable. The project says libzmq and many bindings support PLAIN and CURVE security mechanisms. libzmq is licensed under MPL-2.0; the project says closed-source commercial applications do not need a separate commercial license. Installation guidance covers macOS, Linux distributions and Windows. One documented constraint affects Go’s zmq4 wrapper: it requires ZeroMQ and development files to be installed and cannot be cross-compiled. ZeroMQ is self-hosted and listed at free.