NSubstitute is a friendly substitute for .NET mocking libraries. It has a simple, succinct syntax to help developers write clearer tests. NSubstitute is designed for Arrange-Act-Assert (AAA) testing and with Test Driven Development (TDD) in mind.
It's faking amazing! The easy mocking library for .NET that works great in C# and VB.NET alike. No need to know the difference between a stub, a mock or a spy, everything's a fake! The easy to use, refactoring friendly API makes faking a breeze.