1. An end-to-end publish/subscription messaging system with a middleware architecture, comprising: at least one or more than one messaging appliance comprising a processor and a memory, each messaging appliance being configured for receiving and routing to receive and route messages; and an interconnect utilizing channel-based messaging that routes messages over a first messaging layer based on at least one channel, each channel mapped to a subscription topic, each channel assigned to a communication pathway of a second messaging layer; and a provisioning and management system linked via the interconnect and configured for exchanging administrative messages with each messaging appliance, wherein messages are routed directly from sender to receiver with each messaging appliance configured to coordinate channel capacity among appliances.