C
#include <stdio.h> int main() { printf("Hello, John!"); return 0; }
C#
#include <iostream> int main() { std::cout << "Hello, John!" << std::endl; return 0; }
JAVA
class Hello John! { public static void main(String[] args) { System.out.println("Hello, John!"); } }
JS
document.write('Hello, John!');
PHP
<?php echo 'Hello, John!'; ?>
Python
print "Hello, John!"