我们怎么能用virtualpost集成php？

I have just discovered the virtualpost (vpos) https://code.google.com/p/vpos4php/.

I want to demonstrate with this.But I couldnt understand how it works.And also postnet.php occurs some errors."Warning: require_once(/library/Dahius/VirtualPos/Loader.php): failed to open stream:"

Can you help achiving this?

Thanks.