Zend Optimizer is a well-known piece of software, that's required to execute files protected with Zend Guard. The latter encodes files written in PHP 4, PHP 5, PHP 7 and PHP 8 in order to protect them from reverse engineering and not authorized use, thus guarding copyright protected source code. When you wish to protect your custom script, for example, you are able to employ Zend Guard and your code won't be human readable, but you will also need Zend Optimizer on the server where you host your blog. Lots of pre-made script-driven applications, in particular ones which are paid, also require Zend Optimizer in order to work effectively because their core code is often not free to modify. Internet sites that use the tool are typically quicker since their program code is already optimized and pre-compiled.