What types of executables can be decompiled?

Question

I think that java executables (jar files) are trivial to decompile and get the source code.

What about other languages? .net and all?

Which all languages can

Answer 1

In general, languages like Java, C#, and VB.NET are relatively easy to decompile because they are compiled to an intermediary language, not pure machine language. In their IL form, they retain more metadata than C code does when compiled to machine language.

Technically you aren't getting the original source code out, but a variation on the source code that, when compiled, will give you the compiled code back. It isn't identical to the source code, as things like comments, annotations, and compiler directives usually aren't carried forward into the compiled code.