Web services and service-oriented architectures

Web services, and more in general service-oriented architectures (SOAs), are emerging as the technologies and architectures of choice for implementing distributed systems and performing application integration within and across companies boundaries. In this article we describe Web services from an evolutionary perspective, with an emphasis on the utilization for enterprise application integration and service-oriented architectures. The article also covers basic middleware problems and shows how the solutions to these problems have finally evolved into what we call today Web services.