Cross-platform development with the .NET Execution Environment

In this section, we will discuss what the roles of the full .NET Framework, the Core CLR, and the DNX are. We will start by explaining how the .NET Framework developers have used the Execution Environment since the beginning of .NET. Also, we will see Mono and .NET Core. Then, we will see some guidelines to decide which framework to use. Finally, we will see how the DNX binds everything together.

The traditional .NET Framework

Since the beginnings of .NET, the desktop and console applications have been bootstrapped by executable files and the traditional ASP.NET applications are bootstrapped by IIS using an ISAPI DLL. The applications written in any language supported by .NET are compiled to an assembly. An assembly is an EXE or DLL file containing Intermediate Language (IL). This IL file needs to be compiled to native code as the operating systems and CPUs don't understand IL, and this is called just-in-time (JIT) compiling.

JIT...