The JIT compiler compiles the IL into native code which is then executed by the processor. This MSIL is a platform-independent Intermediate Code that all programs written in languages targeting the .NET Runtime are converted into. The platform independence stems from the fact that all programs written in any .NET Runtime compliant language are compiled to this intermediate code. This is the same for all flavors of the .NET compiler as they target the .NET Runtime and not the host Operating System. However, it should be noted that as with Java's JVM and JIT, we have to have different implementations of the CLR or JIT depending on the platform on which our application would be executed. The .NET Runtime (CLR) is responsible for compiling this intermediate code (MSIL or IL in short) to native code using the Just in Time Compiler (JIT). Note that each block of the MSIL code needs to be Jitted only once and the portion of the source code that is never called is never Jitted. The JIT handles the following:

·         Ensuring type safety and handling violations appropriately

·         Optimizations

·         Assembly Verification