IonCube Loader is an instrument, that is necessary to run files which are encrypted with ionCube PHP Encoder. The latter is an application that is used to make PHP code human unreadable, so as to protect it from reverse engineering and / or illegal usage. Plenty of script-driven apps, especially discussion boards, cms and e-commerce solutions are encrypted with ionCube PHP Encoder, which means that when you purchase a script and you notice that ionCube is among the website hosting environment requirements, you need to make sure that your hosting server has the instrument pre-installed. While it's not that hard to set it up if you have your own server, it is almost impossible to do that on a shared hosting server due to the fact that the PHP environment will have to be precompiled and all clients on the server shall be affected.
