I\'m using XAMPP for Windows and decided to try out Symfony 2.
XAMPP for Windows
Symfony 2
As soon as I get to Symfony Configuration page it recommends me to
Symfony Configuration
For Linux users: Installing php5-intl made it work for me
sudo apt-get install php5-intl
found here: http://www.php.net/manual/en/intl.setup.php