The transport library combines ZeroMQ with Protobufs to create a fast and
efficient message passing system. Asynchronous message publication and
subscription is provided along with service calls and discovery.

Part of the ignition-robotics libraries:
Ignition is a set of simple libraries that provide useful functionality to
bootstrap robot applications. The included libraries encapsulate all the
essentials, such as common math data types, console logging, 3D mesh management,
and asynchronous message passing. Grab the code, start developing, and easily
access other applications like the Gazebo robot simulator.