The standards of the .NET format are public, you can find them on Microsoft and in your .NET SDK (look after "Partition II Metadata.doc"), but they are intended to be more like a reference, not really a guide. So, the truth is that a description of the format can be useful. I mean, there's a huge difference between having the WinNT.h and having the full explanation of its structures and stuff. The documentation given by Microsoft has some explanations, but a lot of passages aren't very clear at all. Of course, it's required that you know quite well the PE File Format. If that's not the case, you should start with that first, otherwise you won't be able to make heads or tails of this article. A little warning: I'm not going to explain how to use the libraries given by Microsoft to access the .NET format, I'm going to explain the format itself. This article is based on the Framework 2.0.