For the applications that scramble your PHP code, yes, you will often need what is called loaders. They sit, typically in the web-root, and decode all the source code which is scrambled. No software as such, just merely loaders - which if Zend is anything like all the others out there, consists of one DLL or SO file - depending on the OS.

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The man who comes back through the Door in the Wall will never be quite the same as the man who went out.