gistfile1.ru

require "sinatra"
get("/") { "Hello World!" }

gistfile2.ph

use Dancer;
use Template;
get '/' => sub { template 'home' };
dance;

gistfile3.pyw

from itty import get, run_itty

@get('/')
def index(request):
    return 'Hello World!'

run_itty()

gistfile4.js

require('express')
get('/user', function(){
  "Hello World!"
})

gistfile5.clj

(ns hello-world
  (:use compojure.core
        ring.adapter.jetty))

(defroutes main-routes
  (GET "/" []
    "Hello World")
  (ANY "*" []
    {:status 404, :body "<h1>Page not found</h1>"}))

(run-jetty main-routes {:port 8080})

gistfile7.lua

require 'mercury'
module('hello', package.seeall, mercury.application)
get('/', function() 
  return "Hello world!"
end)

gistfile8.go

package main

import (
    "web"
)

func hello(val string) string { return "Hello world!" } 

func main() {
    web.Get("/", hello)
    web.Run("0.0.0.0:9999")
}

Scala

package com.thinkminimo.step

class StepExample extends Step {
  get("/") { "Hello World!" }
}