Php Sandbox in a child process which should make it possible to run user supplied PHP code safely.
This is a proof of concept, it works but as far as I know does not run in production anywhere. Because it runs a process for each sandbox it is also much slower than real sandbox solutions.
If you want to offer a scripting solution to your end users you are most likely better off using either the LUA or JavaScript V8 php extensions.
php composer.phar require christiaan/php-sandbox
See the various tests
Does not work on Windows, most likely due to this bug