Apache Qpid Broker-J vs ZeroMQ

Apache Qpid Broker-J is free, open-source Java message-broker software for self-hosted deployments. It stores, routes and forwards messages using AMQP, supporting versions 0-8, 0-9, 0-9-1, 0-10 and 1.0, plus AMQP over WebSockets. Administration is available through REST, AMQP Management and a web console. Routing and queue features include header-based routing, message groups, server-side selectors, dead-letter queues, and last-value, priority and sorted queues. Pluggable persistence supports Derby, SQL and BDB stores. Listed operational features include high availability, producer flow control and flow to disk. Authentication can use LDAP, Kerberos, OAuth2 or SSL client certificates; access control lists and SSL secure connections are supported. The listed current release is 10.1.1, with source archives and tar.gz or zip binaries. Installation documentation covers Windows and UNIX systems. The project uses Apache License 2.0.

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.