Codex
Simple PHP Sources Protection With PHP Extension
Install
Just copy codex.so from /codex/build/ for you php version, if there is no you php version, you can combile php by yourself or send me a mail.
Config
Add this in you php.ini
[codex]
codex.enable = 1
codex.x = "ba1dc1sav0cde5f03"
codex.header = "D.T."
codex.display_ini_entries = 1