What is a JIT compiler and will I require one?
Compilers for .NET do not translate into Intel machine instructions, but into Microsoft Intermediate Language. This language is translated into machine instructions as required when the program is run (or sometimes as the program is installed). The JIT compiler will be part of the operating system. In the future JIT compilers are expected to generate optimal code for the specific CPU chip on which they are running. This will open up a whole new level of performance on the new generation of 64-bit chips.