Zend Optimizer is the runtime needed to execute zend encoded php files.

scripts encoded by Zend Guard or the legacy...Linux family. Installing Zend Optimizer also gives...without the extension. Zend Optimizer 

Zend Guard, the most widely accepted PHP encoding and obfuscation product

Zend Guard provides independent...Zend Guard is comprised of two key components: Zend Guard...license manager and Zend Guard's encoder 

ZendGuard-4.0.1 4.0 is a program to encode your PHP source code.

to Zend Inc. However hackers could decode encoded...Zend encoder (the former name of Zend Guard). The Zend Guard...the support for Zend Optimizer 3.x along