Middleware systems compriseprogrammingmodels, abstractions, protocols, and services to facilitate the design, the development, the integration, and the - ployment of distributed applications in heterogeneous computing environments. Conceptually, the term middleware refers to a layer of software above the networking substrate and the operating system and below the (distributed) application. In practice these boundaries are not clear cut, with middleware functionality moving into and out of these layers. Remote communication, p- lish/subscribe, messaging, and (distributed) transaction...