Be concise.

Be useful.

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Please try to avoid dependencies to third-party libraries and frameworks.

Other implementations
System.out.println("Hello World");
print "Hello World"
echo "Hello World" . PHP_EOL;
import "fmt" 
fmt.Println("Hello World")
document.write("Hello World!");
#include <stdio.h>
printf("Hello World\n");
System.Console.WriteLine("Hello World!");
puts "Hello World"
#include <iostream>
std::cout << "Hello World\n";
println!("Hello World");
with Ada.Text_IO;
use Ada.Text_IO;
Put("Hello World!");
print_endline "Hello World!"
(println "Hello World")
import std.stdio;
writeln("Hello world!");
print("Hello World");
io:format("~s~n", ["Hello, world!"])
write(*,*) 'Hello, world!'
(princ "Hello, world!")
WriteLn('Hello, world!');
print "Hello, world!";
println("Hello, World!")
(display "Hello World")
#import <stdio.h>
NSLog(@"Hello world\n");
System.Console.WriteLine("Hello World!")
write('Hello, world!\n')
print("Hello World")
putStrLn "Hello world!"
IO.puts "Hello World"
print("Hello World")
pragma(msg, "Hello World");
console.log("Hello World");
format("Hello world~n")
"Hello World" |> IO.puts