Metaprogramming in .NET - Kevin Hazzard, Jason Bock

The performance and functionality of a program depends a great deal on its runtime environment, which can vary a great deal from session to session. Metaprogramming is a style of software development that incorporates runtime information into its decision-making. Metaprogramming techniques like reflection and code generation can make your software more adaptive and reusable. The .NET Framework exposes many metaprogramming capabilities including code generation systems, application composition frameworks, and scripting technologies.