It provide the runtime environment to run the php script(phpsandbox).
php sandbox- even its supports oops concepts such as classes and functions to run. we can also save and download the code
Installation
add phpsandbox folder into mod folder or installation done through front end( go to adminstration block,plugins and click on install plugins) also.
To get more info refer below links
http://sandbox.onlinephpfunctions.com/
http://www.fieryprophet.com/blog/detail/sandboxing-untrusted-code-with-phpsandbox