PHP is fine as long as you don't try to do too much with it. For simple GET/POST requests I wouldn't be surprised if there's not much difference performance wise. If you start trying to do any complex processing or data aggregation in PHP (which should probably be done on the database side with queries anyway) then the performance will really fall off a cliff. Especially because PHP is (for web) single threaded. Threading is possible but it'll cause far more headaches than it's worth. Best to keep it simple and use a more appropriate tool if more complex processing is needed.