bcompiler enables you to encode your scripts in phpbytecode,
enabling you to protect the source code.
bcompiler could be used in the following situations

- to create a exe file of a PHP-GTK application (in conjunction with other
software)
- to create closed source libraries
- to provide clients with time expired software (prior to payment)
- to deliver close source applications
- for use on embedded systems, where disk space is a priority.

WWW: http://pecl.php.net/package/bcompiler/