IronPython is just one of the now-numerous languages that run on the .NET framework. In the book so far we have been focusing on the different ways that we can access features of the .NET framework from within the IronPython world-view. In this final part of the book, we look at the other side of the story, working with IronPython from other .NET languages. We start this look by creating class libraries with C# and VB.NET specifically to use from IronPython.