This sample demonstrates the use different development languages in a single project. This sample creates two assemblies. The first is a library or DLL assembly that defines a simple base class written in managed extensions for C++. The second assembly is an executable assembly that defines three derived classes written in C#, VB, and IL (Intermediate Language). These types derive from each other and ultimately from the base class written in managed C++. Finally, the executable creates instances of each of the derived types and calls a virtual method for each. The .NET Framework is an environment where various developers can work together seamlessly while developing in their language of choice.