This chapter shows us what the MVVM pattern depends on and how to implement it in our application. For sure, there are many advantages of using MVVM and each of them were listed here. A huge part of XAML—data templates, bindings, and MVVM commands were described with many examples of real-life usage. There are some third-party libraries that can be used to improve performance and accelerate work, one of them being the MVVM toolkit described in this chapter. In the end, we had a brief description of what unit testing is and how to implement it in our application.