Common Intermediate Language (CIL) is the lowest-level human-readable programming language in the .NET Framework and in the Common Language Infrastructure. Languages which target the .NET Framework compile to CIL, which is assembled into bytecode. CIL resembles an object oriented assembly language, and is entirely stack-based. It is executed by a virtual machine. The primary .NET languages are C#, Visual Basic .NET and Managed C++.

With the beta releases of the .NET languages, CIL was originally known as Microsoft Intermediate Language (MSIL). Due to standardization of C# and the Common Language Infrastructure the bytecode is now officially known as CIL. Because of this legacy, however, CIL is still often referred to as MSIL. This is especially true of longtime veterans of the .NET languages.

CIL also is an acronym for C Intermediate Language which is a is a high-level representation along with a set of tools that permit easy analysis and source-to-source transformation of C programs. * CIL (berkeley.edu)

Example CIL code

This is a Hello world program in CIL.

.assembly HelloWorld
.class auto ansi HelloWorldApp
{
     .method public hidebysig static void Main() cil managed
     {
          .entrypoint
          .maxstack 1
          ldstr "Hello world."
          call void [mscorlib]System.Console::WriteLine(string)
          ret
     }
}

External links

• Common Language Infrastructure (CLI ) - Partition III - CIL Instruction Set
• Tutorial including CIL (called MSIL in the tutorial) by Aleksey Nudelman