com.rabbitmq.client The client API proper: classes and interfaces representing the AMQP connections, channels, and wire-protocol framing descriptors.
com.rabbitmq.client.impl Implementations of interfaces specified in the client API, and their supporting classes. Non-core utilities and administration tools. JSON reader/writer and utility classes. JSON-RPC client and server classes for supporting JSON-RPC over an AMQP transport.
com.rabbitmq.utility Utility package of helper classes, mostly used in the implementation code.