Dynamic Library: Do you need to export variables of a class?

[babaliaris]

and why the dll interfaces need to be 'C' and not C++!

Well if I'm compiling the project myself, I won't probably have any problems but if others need to compile it in other operating systems too , from what i read from your links i will have a problem. If i program every dll in C i won't have problems with the compilers right?