PostSharp

PostSharp was designed to be an extensible platform for enhancement of .NET assemblies, that is: PostSharp transforms assemblies after compilation.
Pretty abstract, isnt it? Not so much. It has great applications. PostSharp Laos, a Lightweight Aspect-Oriented Solution, provides aspect-oriented programming (AOP) to .NET Developers without the learning curve.
PostSharp is a tool that can reduce the number of lines of code and improve its logical decoupling. Therefore its helps you delivering higher stability, cleaner design, and cheaper source code maintenance.
Have you already implemented things like transaction management, logging, caching, or security? In each method, you had to write a same dozen of lines of code, right?
With PostSharp, you can encapsulate these aspects as custom attributes.
You can make your own custom attributes that will really add new behaviors to your code! This is sometimes called aspect-oriented programming (AOP) or policy injection.
PostSharp transparently inserts itself in the build process and post-processes the compiled assembly. Since PostSharp works at MSIL level, it supports virtually all static languages targeting the .NET Framework.Limitations in the unregistered version45-day trial