Experimental Front Controller that can return content in multiple formats.

index.php

<?php
require "startup.php";
$action = (isset($_REQUEST['action']) && $_REQUEST['action']!="" && file_exists(__DIR__."/{$_REQUEST['action']}.php")) ? $_REQUEST['action'] : "sources";
?>
<?php if(! isset($_REQUEST['request_type']) || $_REQUEST['request_type']!="ajax"): ?>

<?php include('header.php');?>

<div id="content">

<?php endif;?>
<?php require __DIR__."/{$action}.php";?>
<?php if(! isset($_REQUEST['request_type']) || $_REQUEST['request_type']!="ajax"): ?>

</div>

<?php include('footer.php');?>

<?php endif;?>