IonCube Loader is a software instrument, that's needed to run files that are protected with ionCube PHP Encoder. The aforementioned is an app that is used to make PHP code human unreadable, as a way to protect it from reverse engineering and / or not authorized usage. Various script-driven apps, particularly discussion forums, cms and e-commerce solutions are protected with ionCube PHP Encoder, which means that if you acquire a script and you find that ionCube is among the hosting environment requirements, you need to ensure that your web hosting server has the tool 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 shall have to be precompiled and all clients on the server shall be affected.