Where is the point in using a Serverside Software, that does nothing on the Clientside. On a client without a server?
I think there are much better ways to do that, than in PHP. I would use Java (if you need the os-independence)...
But I recently had a look at some php editors and at least one of them offered a debugging and execution feature for PHP Scripts... I'm not sure if this needed a webserver or not, but you could have a look at it...
http://phpcoder.stsoft.cjb.net/
http://www.soysal.com/PHPEd
cya Rob