PHP 5.3 seems to be missing Intl extension by default

Question

My system is Ubuntu 12.04, PHP 5.3, and I'm trying to run some basic Intl code like this:

<?php
$coll  = collator_create('en_US');
$result = collator_compare($coll, "string#1", "string#2");

and it outputs

PHP Fatal error:  Call to undefined function collator_create()

Wasn't Intl extension supposed to be bundled with PHP since version 5.3?

PHP was installed via apt-get with this command line (I don't use Apache):

apt-get install php5 php5-cli php5-mysql php5-cgi php5-fpm php5-curl php-apc php5-memcache php5-memcached php5-common php5-gd php-xml-parser php-pear php5-imap php5-mcrypt php5-xdebug php5-suhosin

And here is what php -v produces:

PHP 5.3.10-1ubuntu3.5 with Suhosin-Patch (cli) (built: Jan 18 2013 23:40:19) 
Copyright (c) 1997-2012 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2012 Zend Technologies
    with Xdebug v2.1.0, Copyright (c) 2002-2010, by Derick Rethans
    with Suhosin v0.9.33, Copyright (c) 2007-2012, by SektionEins GmbH

Answer 1

You have specify --enable-intl when installing to use the bundled version of intl, or you can install it via PECL. See: http://www.php.net/manual/en/intl.installation.php

apt-get install php5-intl will also work.