Just to put an argument in the other direction to everyone else...
I feel slightly uncomfortable thinking of PHP as a programming language because I'm not convinced you end up with a program. You don't leave your PHP app running, rather a PHP page is requested and is loaded and processed in order to generate an output page, with side-effects like DB changes, etc.
None of this means PHP can't technically be described as a programming language but I think it's reasonable to separate it somehow from Java/C++ where a program can be left running with some concept of state. Each PHP file is surely its own 'program' since you can request any PHP page... there's no entrypoint to a PHP web-application except the convention of calling the right pages.
