how to save copyright?

[eluser]nelson.wells[/eluser]
Look into Zend Optimizer or Ion Cube. They basically give you the ability to encrypt php files so that they cannot be edited. Even if you want to leave your app open source, you can set up an 'authorization file' with a secret key, and that authorization file will be encrypted. Check against the value in the file in every controller, and if it passes the controller loads or if it fails the controller alerts the user and then aborts.

I believe that is how ExpressionEngine protects the 30 day demo of their most recent release.