I think one of the key languages for the web at the moment this Java and Python.
I picked those two languages as are both supported on googles cloud services.
Having them there means you have the processing power of google cloud.
PHP is a great language and I know it better then both Java and Python but it doesn't have a cloud hosting solution. If your site gets digged or boing boinged can your app scale with cloud services.
I am still open to other ideas a go.