One of a requirement given to me recently was tricky. I really amazed after providing solution for the requirement. Thanks .NET you made my life easier :) It is a ASP.NET application developed in .NET 2.x. The deal is user will configure certain parts of whole class libraries in application configurtion file. For instance, user would say, "I want to use exception management block by using X assembly instead of Y assembly", he will just change few entries in configuration file the entire application...