Bash

echo "Hello, world!"

Basic

PRINT "Hello, world!"​

CoffeeScript

console.log "Hello, world!"

Go

package main
import "fmt"
func main() {
    fmt.Println("Hello, world!")
}

JavaScript

console.log("Hello, world!");

PHP

<?php echo 'Hello, world!'; ?>

Python

print("Hello, world!")

Ruby

puts "Hello, world!"

SQL

SELECT 'Hello, world!';