Can all applications be decompiled? [duplicate]

This question already has answers here: Closed 11 years ago.

Possible Duplicate:

What types of executables can be decompiled?

It's pretty popular to decompile the Minecra开发者_如何学JAVAft classes to edit and add your own mods. Is every Java application decompilable? Does it stop at Java applications?

I'm a little concerned about this, but no one else seems to be so maybe I just don't understand. What's stopping people decompiling Microsoft Word and making their own custom changes? Or decompiling World of Warcraft and stealing interesting bits of their code?

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Byte code (as java and c# get compiled into) can easily be decompiled. There are ways around it as in obfuscation and other alternatives. C and C++ get compiled into native machine code, and is difficult to "decompile". But someone with the correct skillset could be able to reverse engineer it anyway.

Edit: Note that obfuscation will not make it harder to decompile the byte code - it will be just as easy, but the code will be harder to make any sense of.