Install APC on Ubuntu with PHP 5.3

Installing the APC with PHP5.3 is straightforward (when you know how):

1. Install the required packages:

sudo apt-get install php-pear php5-dev apache2-threaded-dev

2. Install APC:

sudo pecl install apc-3.1.4

3. Create file /etc/php5/conf.d/apc.ini with the following content:

extension=apc.so

4. Restart Apache:

sudo /etc/init.d/apache2 restart

After restarting the Apache2 web server apc.ini section should be included in the phpinfo() output.