I'll expand a little on what's already been said.
You can use PHP on X10 Hosting, but depending on what commands you try to use, you may need to request X10 upgrade the PHP version on your account. X10 has secured PHP, removing 'bad' commands. If your application tries to use these bad commands, it won't work. In your account panel (
http://www.x10hosting.com/account) is an option for PHP. Just choose the version you need and enter a detailed description of why you need that version, and they'll get back to you as soon as they can.