Recently I has been looking at various mocking frameworks, and found Duck Typing Project (by David Meyer AKA “deft flux”) – a .NET class library written in C# that enables duck typing for any .NET language. Current release is a bit oldish, but David promised to finalize version 1.0 and start working on 2.0, which will include a name change to something along the lines of “dynamic typing” instead of “duck typing” to reflect the implementation of more dynamic typing concepts than just duck typing, as well as add some .NET 3.5 features like extension methods.

How Duck Typing Benefits C# Developers by Phil Haack provides quick into to duck typing and its benefits.