Obfuscation allows you to scramble your PHP code so it is hard to read by humans. One of the best Obfuscation for PHP I know is PHP Obfuscator.

Unlike some other solutions PHP Obfuscator does not require special server side libraries or server components to work properly. This allows you to target a broad range of servers that support PHP. This may be useful for commercial products looking to secure their source code.

Key Features

• Encode and obfuscate PHP code, functions and variables

• Exclude particular variables, functions or files from obfuscation and encoding

• Process large projects with command line tools and project files

• Open source and 100% free