The three generations of component model are: 1. OLE Technology 2. COM Technology 3. .NET Technology OLE Technology Microsoft developed Object Linking and Embedding technology to enable easy inter-process communications among various applications. OLE was intended primarily to embed an application within a document. Say for example; spread sheets with in word processing documents. It also enables one application to manipulate objects located in another application. COM Technology COM stands for Component Object Model. This is a technology that one uses to define components and manipulate it. In this technology a program is divided into number of independent but interoperable components each one offering a particular service. Think of COM as a shell that one wraps around components, and that define how message is passed between clients and component objects. The advantages of this technology is:
· It reduces the software complexity. · Enables distributed development across multiple organizations and departments. · It improves the software maintainability. .NET Technology The .NET technology is a very powerful and highly productive for developing windows as well as web applications. Its predecessor Microsoft COM technology provides a standard binary mechanism for inter-module communication. The unique feature of .NET is the multi-language support that it provides. Microsoft .NET provides an intermediate language called Microsoft Intermediate Language (MSIL) for cross-language integration. Compiling source program in to MSIL enforces the interoperability among various .NET languages. In addition to Intermediate Language, .NET also hosts other technologies and tools, which makes it a special environment to develop windows and web applications.