Most user applications benefit from the ability to be extended by other developers. It's often easier and more efficient to extend an existing application that users are already familiar with and trained on than it is to develop one from scratch. Thus, extensibility makes your application more attractive. You can build extensibility into your application by supporting features like plug-ins or macros. This is easily accomplished using the .NET Framework even if the core application isn't a .NET Framework app. In this article, the author describes extensibility features of the .NET Framework including late binding and reflection and how to us..