Companies want to apply the benefits of component software, rapid reuse, broad industry support, and availability of thousands of components, across shared applications that operate on multiple machines. These types of applications are referred to as "three-tier" or "n-tier" applications, where "tiers" of application logic, presentation services, business services, and information retrieval and management services, are broken into different components that can communicate directly with each other across a network. To the end user, these applications appear as a seamless extension of their existing desktop environment. For the IT manager, they represent the opportunity to apply the economics and flexibility of desktop development across a broader set of application problems.
For example, a business may deploy a new sales management system based on a multitier application design using components. The application includes different order entry components, each one designed for a separate sales channel. These components all use a common, single tax calculation component that runs on a server. As tax laws change, the company only has to change the tax component located on the server, without having to retrofit the order entry components for each of the different sales channels.
DCOM is an ideal technology for multitier applications because it enables
ActiveX components to work across networks, enabling developers to easily build systems that span machine boundaries. In the scenario described above, developers integrate components together without having to worry about network programming, system compatibility, and integration of components built from different languages.
This can lower the cost and complexity of building distributed applications from components. DCOM leverages the investments companies have already made in ActiveX by providing the following benefits: