I've read many letters in this list about compiling or rather encoding php code.
Here is my idea(free 🙂).
I'm useing RSA files with php code encoding and perl parser which changes all paths and decode code.
There is also C deamon which doesn't allow users to use perl parser but only apache user.
I'm thinking about apache simple module, but give me time 🙂... I'm still learning.
Any sugesstion or new ideas? Email me
Maybe I'm not thinking good...
But it is just idea.