Preferred Method of PHP Byte Encoding

Question

I am writing a web app for a company that wants to host the app on its servers. I want to protect the source code for two reasons. The first is the obvious closed source business model. The second is source code protection. I don't want them to be able to edit the source code (They aren't competent). I've looked into things like the Zend Encoder. What have you used? Are there free options? Do they run on Windows and/or Linux?

Answer 1

I chose to go my selling a support service. All help (FAQs, tutorials, support) is not shipped with the product. To login to the support server, they must provide a company ID (via POST), Thanks for the tips.