print("Hello, world!")

#include <stdio.h>

int main() {
    printf("Hello, world!\n");
    return 0;
}

#include <iostream>

int main() {
    std::cout << "Hello, world!" << std::endl;
    return 0;
}

using System;

namespace MyCSharpProject
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello, world!");
        }
    }
}

public class Main {
    public static void main(String[] args) {
        System.out.println("Hello, world!");
    }
}

const http = require('http');

const hostname = '127.0.0.1';
const port = 3000;

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello, World!');
});

server.listen(port, hostname, () => {
  // console.log(`Server running at http://${hostname}:${port}/`);
});

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

fn main() {
    println!("Hello, world!");
}

from flask import Flask

app = Flask(__name__)

@app.route('/')
def index():
    return 'Hello, World!'

if __name__ == '__main__':
    app.run(debug=True)

# Django's command-line utility for administrative tasks
import os
import sys

if __name__ == '__main__':
    os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'django_project.settings')
    try:
        from django.core.management import execute_from_command_line
    except ImportError as exc:
        raise ImportError(
            "Couldn't import Django. Are you sure it's installed and "
            "available on your PYTHONPATH environment variable? Did you "
            "forget to activate a virtual environment?"
        ) from exc
    execute_from_command_line(sys.argv)