Infer.NET is an open source library that can be used to create probabilistic programming systems. We can use Infer.NET to solve many different kinds of machine learning problems, such as classification, recommendation, and so on. In this article, I am going to introduce how to use the infer.NET library in Visual Studio 2017 Community. Infer.NET supports both C# and F#, and I am going to use C# in this article.