What are the valid signatures for C's main() function?

Question

What really are the valid signatures for main function in C? I know:

int main(int argc, char *argv[])

Are there other valid ones?

Answer 1

http://en.wikipedia.org/wiki/Main_function_(programming)#C_and_C.2B.2B

Besides the usual int main(int argc, char *argv[]) and the POSIX int main(int argc, char **argv, char **envp), on Mac OS X also supports

int main(int argc, char* argv[], char* envp[], char* apple[]);

Of course it's Mac-only.

On Windows there's

int wmain(int argc, wchar_t* argv[], wchar_t* envp[]);

as the Unicode (actually, wide-character) variant. Of course there is WinMain too.