A plug-and-play handler for Paypal's Instant Payment Notification system to be used with JMSPaymentCoreBundle and JMSPaymentPaypalBundle. Includes support for Refunds. It's assumed that you are using the JMSPayment bundles to handle the checkout workflow as described here.
It's as simple as:
<?php namespace Acme\SomeBundle\Controller;
use Symfony\Bundle\FrameworkBundle\Controller\Controller