Basic stub for mod_rewrite-like behaviour using PHP 5.4's development server

index.php

<?php
// To the extent possible under law, I (Stephan Sokolow) waive all copyright and related or 
// neighbouring rights to this code snippet. (Though it'd still be nice if you mention me)

// If we're running under `php -S` with PHP 5.4.0+
if (php_sapi_name() == 'cli-server') {

    // Replicate the effects of basic "index.php"-hiding mod_rewrite rules
    // Tested working under FatFreeFramework 2.0.6 through 2.0.12.
    $_SERVER['SCRIPT_NAME'] = str_replace(__DIR__, '', __FILE__);
    $_SERVER['SCRIPT_FILENAME'] = __FILE__;

    // Replicate the FatFree/WordPress/etc. .htaccess "serve existing files" bit
    $url_parts = parse_url($_SERVER["REQUEST_URI"]);
    $_req = rtrim($_SERVER['DOCUMENT_ROOT'] . $url_parts['path'], '/' . DIRECTORY_SEPARATOR);
    if (__FILE__ !== $_req && __DIR__ !== $_req && file_exists($_req)) {
        return false;    // serve the requested resource as-is.
    }
}

// TODO: The rest of your index.php goes here