As XML lays the foundation to help you to support current and future Web services standards, rich-client architecture enables you to extend services for your customers.

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by Sandip H. Mandera, staff technical marketing engineer, Intel Corp.

The purpose of this paper is to help Independent Software Vendors (ISVs) re-architect existing applications to take advantage of rich-client Web services. No doubt you have started thinking of Web services. You recognize their value and look forward to having all your systems tied loosely together via Web service interfaces. Perhaps exposing functionality to the outside world may even cultivate new revenue streams. But first things first: you need a plan.

Although Web services are relatively simple, re-architecting an existing application isn't. Where do you begin? This article will help you identify opportunities and easily adopt rich-client Web services within your existing architecture.

Introduction
Service-oriented architecture (SOA) allows existing software components (residing on a network) to be published and discovered by each other. SOA builds on existing object-oriented methodology by adding the notion of service. This allows software architects to model programming solutions in terms of services offered by components to anyone, anywhere over a network. In other words, any application residing anywhere on any computer system is able to interact with any service anywhere over the network.

So where do Web services fit? Well, if the only language I could speak were object-oriented modeling, then I would say that a Web service is an instance of SOA. Web services are programmatic components that can be published, discovered, and invoked over the network using open, interoperable protocols. Figure 1 shows a schematic representation of Web services.

Figure 1. Components of Service-oriented Architecture.