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Zend Guard Loader support (formerly Zend Optimizer)
Zend Optimizer is available (for old hostings which have the obsolete PHP 5.2.x version) and can not be disabled.
Since PHP 5.3.x, Zend Optimizer has been replaced by Zend Guard Loader.
With regard to the ZendOPCache exootension you should consider a Cloud Server under PHP 5.5 minimum in order to enable it.