AMQP
Advanced Message Queuing Protocol. AMQP 1.0 is both an OASIS standard and an International Standard (ISO/IEC 19464). Wire-level binary protocol defining nodes, links, sessions, and frames. Mission per the spec home: "To become the standard protocol for interoperability between all messaging middleware." Major implementations include Microsoft Azure Service Bus, Apache ActiveMQ Artemis, and SwiftMQ for 1.0; RabbitMQ remains the canonical AMQP 0-9-1 implementation.