Here is a list of the Hello World Programs for different languages:

C

#include
int main()
{
printf("Hello World!");
}

C++

#include
int main()
{
cout << "Hello World!" << endl;
}

C#

public class HelloWorld
  public static void Main()
  {
    System.Console.WriteLine("Hello World!");
  }

Java

class HelloWorld {
static void main(String[] args)
{
System.out.println("Hello World!");
}

SHELL

echo "Hello World"

Python

print "Hello World!\n"

Ruby

puts "Hello World!"

Perl

print "Hello World!\n";

PHP

  <?php
    print "Hello World!";
  ?>

This is the simplest form of Hello World for most of these languages.