The .NET Runtime Environment

In the past, writing modules that could be called from multiple languages was difficult. Code that is written in Visual Basic can’t be called from Visual C++. Code that is written in Visual C++ can sometimes be called from Visual Basic, but it’s not easy to do. Visual C++ uses the C and C++ runtimes, which have very specific behavior, and Visual Basic uses its own execution engine, also with its own specific— and different—behavior.