Many PHP developers need to protect their source code when they distribute it to customers, to minimize the chances of their work being altered or copied without their permissions.

The PHP Application Packer fills the gap between simple obfuscators and ultimate tools. For this package packing means minifying, obfuscation, compressing with ZIP.

http://www.phpclasses.org/blog/package/9574/post/1-PHP-Source-Code-Protection-Solutions.html