Part III illustrates three applications of C#. The first is the building and managing of components. Because many of the features of C# were designed expressly to facilitate their creation, components are an important part of C# programming. The second application uses C# to create a Windows program using the classes defined by System.Windows.Forms. Finally, the book concludes by applying C# to a “pure code” example: a recursive-descent parser that evaluates algebraic expressions.