Component-based models for distributed systems

Much larger flexibility of software adaptability is necessary to the destination platform and the user requirement in distributed systems. Component-based models are becoming increasingly ubiquitous as enabling technology for modern distributed system applications. Software modules and components have always played a key role in the systems. The fundamental contribution of component-based models lies in making the property of the distributed systems a core requirement. In this paper the component-based models, such as COM+, EJB, CORBA and OSGi, are evaluated, and how deployment modelling is described. To illustrate the component models, an application to POP3 Web service component is implemented in Visual Studio .NET.