microRouter

index.php

<?php
require 'Route.php';

$route = new Route;
$route->on('/', function(){
  echo 'home';
});
$route->on('/blog', function(){
  echo 'blog';
});
$route->run();

Route.php

<?php
Class Route{
  $routes = array();
  function on($url,callable $call){
    $this->routes[$url]=$call;
  }
  function notFound(callable $call){
    $this->routes['404']=$call;
  }
  function run(){
    $this->routes[isset($this->routes[$_SERVER['PATH_INFO']])?$_SERVER['PATH_INFO']:'404']();
  }
}