The Loader is a .dll file or .so file (depending on the server’s operating system) which PHP uses to decode scripts encoded with the ionCube Encoder. PHP has the ability to open .dll (or .so) files at the moment a script is run. The dl function in PHP is used for this purpose. This mechanism, when used to launch the ionCube Loader, is called run-time loading.
Please note that the following steps will explain how to install ioncube loader on a linux server. Also keep in mind that you will need root shell access to the server.
1 – Download ionCube from the source to your server. Make note that the following link is for Linux 64 Bit.
wget http://downloads.ioncube.com/loader_downloads/ioncube_loaders_lin_x86-64.tar.gz
2 – Now we extract the  downloaded file.
tar -zxvf ioncube_loaders_lin_x86-64.tar.gz
3 – Lets move the ioncube folder to a new permanent location.
mv ioncube /usr/local
4 – Its time to edit your php.ini file.
pico /usr/local/lib/php.ini or nano /usr/local/lib/php.ini
5 – Add the following to your php.ini file below [ZEND]
zend_extension=/usr/local/ioncube/ioncube_loader_lin_5.2.so
6 – Now you need to restart your apache server and your done.
service httpd restart