[Pugged] Using environment variables

[Claus]

Hi

Which one is the preferred way to get the environment variables from the 
web server (as listed in phpinfo()) and why?

Examples:
result = $HTTP_ACCEPT_LANGUAGE;
result = $_SERVER['HTTP_ACCEPT_LANGUAGE'];
result = getenv ("HTTP_ACCEPT_LANGUAGE");
... any others that I forgot

Thanks,
   Claus