Lots of licensed and some free script-driven applications have protected code, that isn't human readable. The concept behind this is to prevent the reverse engineering and the unwanted use of such applications. Among the most popular encryption software instruments used for this purpose is known as Zend Guard and it's very popular as it can be used to modify any type of PHP 4, PHP 5, PHP 7 and PHP 8 code. The only method for the encrypted files to work effectively on a web server subsequently is when one more instrument called Zend Optimizer is there. In the event that you wish to employ any kind of paid web software which needs Zend Optimizer, you need to ensure that it's installed on the server where you will host your site. In addition, websites which require the tool can perform better since their code is already precompiled and optimized, meaning that it's executed more quickly.