What is APC?
From php.net: “The Alternative PHP Cache (APC) is a free and open opcode cache for PHP. It was conceived of to provide a free, open, and robust framework for caching and optimizing PHP intermediate code.” So basically we can use APC to squeeze even better performance out of @Mail. Installing APC APC is a PHP PECL extension so I will cover using the pecl command to insall APC. If you find that pecl is not available on your system performing the following command for your system should install it: • Ubuntu/Debian: apt-get install pear • FreeBSD: pkg_add -r php5-pear • RedHat Linux (inc Centos, Fedora etc): yum install php5-pear You will also need the apache apxs tool.