- CapnProto - Cap’n Proto serialization/RPC system - core tools and C++ library
- Comet - Modern (idiomatic>`_ binding between COM and C++
- rabbitmq-c - C-language AMQP client library for use with v2.0+ of the RabbitMQ broker.
- ZeroMQ - provide an abstraction of asynchronous message queues, multiple messaging patterns, message filtering (subscriptions>`_, seamless access to multiple transport protocols and more.
- ZMQPP - “high-level” C++ binding for ZeroMQ/0mq/zmq