2. Service-oriented architecture

Launched by the Gartner Group, an American analyst firm, the notion of SOA (for Service-Oriented Architecture) defines a model of interaction between applications involving loosely coupled connections between various software components (or agents). In this model, a "service" is defined as an action carried out by a "supplier" component for a "consumer" component, possibly based on another operating system or located on another machine. While the broad outlines of SOA are reminiscent of some of its predecessors, such as the OMG's Distributed Object Model (Corba for Common Object Request Broker Architecture) or Microsoft (DCOM for Distributed Component Object Model), the objectives and means used differ considerably.

The SOA model is based on a foundation of standards and protocols made popular by the widespread use of the Web. It presupposes that...