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Get Value From Rich Clients
See how rich clients let you leverage and aggregate remote Web services.
by David S. Linthicum

December 6, 2004

As we move quickly toward service-oriented architectures (SOAs), the need to provide a better user interface—one that functions for all practical purposes as a native application—on top of these services has arisen.

Enter the term rich client, and a new generation of application development technologies, standards, and approaches that allow architects to abstract exposed services to users more dynamically, providing many advantages over the traditional HTTP "pump and pull" mechanisms for portal and Web application creation today. In other words:

A rich client is a small piece of software that runs on the client to leverage and aggregate remote Web services as well as local and remote data, allowing them to appear as a single, unified, native application.

The movement toward rich clients seems to be a natural progression in a new service-oriented world that allows both developers and architects to gain maximum value from the existing set of services, thus supporting reuse and reducing total cost of ownership. You can truly assemble applications from component parts along with interfaces that support them. The interfaces appear richer than traditional browser-based applications and are therefore more productive for the end user and valuable to the enterprise. Think of rich clients as a return back to client/server types of interfaces.

The Value of Portals
Rich clients are new types of portals, providing a point of integration at the user interface. Portal-oriented application integration allows you to view a multitude of systems—both internal enterprise systems and external trading community systems—through a single-user interface or application. You can benefit from portal-oriented application integration by avoiding the back-end integration problem altogether; it adapts the user interface of each system to a common user interface (aggregated user interface)—most often a Web browser. As a result, it integrates all participating systems through the browser (see Figure 1).

The use of portals to integrate enterprises has many advantages. The primary one is that there is no need to integrate back-end systems directly between companies or within enterprises, which eliminates the associated cost or risk of more invasive integration approaches. What's more, you usually don't have to worry about circumventing firewalls or application-to-application security, because portals typically do nothing more than Web-enable existing systems from a single enterprise. With portals, you simply connect to each back-end system through a point of integration (user interface, database, application server, etc.) and externalize the information into a common user interface (Web browser). Using rich clients simply means you change the technology and underlying mechanisms, not the notion of a portal.

The advantages of portal-oriented integration are clear:

• It supports a true noninvasive approach that allows organizations and users, inside or outside of the company, to interact with a company's internal systems through a controlled interface accessible over the Web or intranet.
• It is typically much faster to implement than realtime information exchange with back-end systems, such as the information-oriented approaches using integration servers.
• Its enabling technology is mature, and you can learn from many examples of portal-oriented application integration that already exist.

However, traditional portals are not perfect. The use of the Web as a platform has many limitations and, although still a valuable part of an architecture, might require a facelift as we move to more sophisticated forms of computing, including SOAs. Indeed, we are looking to rich clients as the new interfaces for portals and other Web-based applications.