Can it possible to do that?
So i can distribute my program to anyone but my source.
Well, with PHP your program is your source. So if you want to distribute it, AFAIK you can't do much to protect the source except putting a license on it.
Go buy the Zend Encoder from zend.com. Don't complain about the price; if you want your code compiled then an investment is necessary.
You can also get scripts / programs which will rewrite you PHP scripts with crazy variable and function names, and impenetrable syntax, making it virtually unreadable.
Or, rewrite it in Python, and distribute the bytecode 😉
I've seen people do that to their HTML using Javascript. From what I've seen, it only takes a little time and some coding skills to reverse the process though. But it's god awful to look at, you'll probably scare most everyone away!
As toma mentioned, check out www.zend.com
To help programers hide your php code, I create encoder4php. It's only US$ 59.00, but you can try it for free at http://encoder4php.pag1.com