Microsoft Intermediate Language

[diagram taken from samspublishing.com]

Article 1:

All .NET code, regardless of the language syntax used, compiles to
Intermediate
Language (IL) code. IL code is the only code the CLR
understands; it doesn't
understand C#, Visual Basic, or any other
developer
syntax. It's IL that gives
.NET its multilanguage
capabilities; as long as
an original source language can
be compiled to
IL, it can become a .NET
language. [full article here]

Article 2:

Simplest Program written in IL
We will start our journey with the classic
example of Hello World, but with a little twist. Open your favorite text editor,
create a new text file and name it HelloWorld.il and punch in the following
lines of code:
.method void HelloWorld()
{
ret
} [full article here]