#include<bits/stdc++.h>
using namespace std;
int main(){
    cout<<"Hello World! I'm a C++ program.";
    return 0;
}

C :

#include<stdio.h>
int main()
{
 printf("Hello World! I'm a C++ program.\n");
 } 

C++ :

#include <iostream>
using namespace std;
int main ()
{
  cout << "Hello World!";
  cout << " I'm a C++ program.";
  return 0;
} 

Python :

# coding=utf-8
print("Hello World! I'm a C++ program.")