what language is dotnet executable written in?

I thought it would be Common Intermediate Language, but in notepad it does not look like that at all. Does it just look uglier in reality than in tutorials? Or is it some byt开发者_StackOverflowecode form that is further compiled from CIL?

It's CIL is the name of the binary format, not of the "assembler" you're thinking of.

Can you possibly imagine that .NET assemblies would be text files?

A .NET executable is a binary file that has a PE header (same as a native executable, but with slightly different values). The PE header tells the OS to load the CLR, which in turn loads the assembly.

The content beyond the header is a binary representation of the CIL code, plus some metadata and other stuff. The text you see in tutorials is the text representation of CIL, in much the same way that the assembly language code you see in a tutorial about assembly language programming is just the text representation of the binary machine code.

See http://www.yetanotherchris.me/home/2010/7/12/inside-net-assemblies-part-1.html (among many others) for more information.

A .Net executable is usually not written, it is compiled from another language such as C#, F# or VB.Net.

The contents of a .Net executable can be viewed with the ILDASM tool.

The contents are first a manifest which is used for reflection, signatures or other meta-code purposes.

Secondly there are the MSIL instructions themselves. These are in a kind of bytecode format, but ILDASM will show you what the instructions are.

And there are sometimes resources such as imagery, sounds or other content packed into the executable.

The executable is just-in-time compiled to native code either during installation (I think this is uncommon), or as a precursor to execution. The resulting native code can be stored for reuse. (This is what I was told during PDC 2001, might be "out of date".)