_02_composer.json

    "require": {
        "php": ">=5.3.3",
        "symfony/symfony": "2.1.*",
        "doctrine/orm": ">=2.2.3,<2.4-dev",
        "doctrine/doctrine-bundle": "1.0.*",
        "twig/extensions": "1.0.*@dev",
        "symfony/assetic-bundle": "2.1.*",
        "symfony/swiftmailer-bundle": "2.1.*",
        "symfony/monolog-bundle": "2.1.*",
        "sensio/distribution-bundle": "2.1.*",
        "sensio/framework-extra-bundle": "2.1.*",
        "sensio/generator-bundle": "2.1.*",
        "jms/security-extra-bundle": "dev-master",
        "jms/di-extra-bundle": "dev-master",
        "kriswallsmith/assetic": "1.1.*@dev",
        "friendsofsymfony/rest-bundle": "0.11.*@dev",
        "jms/serializer": "1.0.*@dev",
        "jms/serializer-bundle": "1.0.*@dev"
    },

_03_AppKernel.php

<?php

class AppKernel extends Kernel
{
    public function registerBundles()
    {
        $bundles = array(
            new Symfony\Bundle\FrameworkBundle\FrameworkBundle(),
            new Symfony\Bundle\SecurityBundle\SecurityBundle(),
            new Symfony\Bundle\TwigBundle\TwigBundle(),
            new Symfony\Bundle\MonologBundle\MonologBundle(),
            new Symfony\Bundle\SwiftmailerBundle\SwiftmailerBundle(),
            new Symfony\Bundle\AsseticBundle\AsseticBundle(),
            new Doctrine\Bundle\DoctrineBundle\DoctrineBundle(),
            new Sensio\Bundle\FrameworkExtraBundle\SensioFrameworkExtraBundle(),
            new JMS\AopBundle\JMSAopBundle(),
            new JMS\DiExtraBundle\JMSDiExtraBundle($this),
            new JMS\SecurityExtraBundle\JMSSecurityExtraBundle(),
            new JMS\SerializerBundle\JMSSerializerBundle($this),
            new FOS\RestBundle\FOSRestBundle(),
            ...(snip)
        );
        // ...(snip)
    }
    // ...(snip)
}

FosRestBundle.php

<?php

namespace Euphory\StoreBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Method;

use FOS\RestBundle\View\View;

class UserController extends Controller
{
    /**
     * @Route("/rest/users", defaults={"_format"="json"})
     * @Method({"GET"})
     */
    public function allAction()
    {
        $data = array('users' => array('taro', 'hanako'));
        $view = View::create();
        $view->setData($data);

        return $this->get('fos_rest.view_handler')->handle($view);
    }

    /**
     * @Route("/rest/users/{id}", requirements={"id" = "\d+"}, defaults={"_format"="json"})
     * @Method({"GET"})
     */
    public function getAction($id)
    {
        $data = array('user' => 'taro');
        $view = View::create();
        $view->setData($data);

        return $this->get('fos_rest.view_handler')->handle($view);
    }
}