title: Accurately determine the type of OS PHP is running on
body: <p>I need to determine the type of OS the PHP server is running on.
  By type, I mean strings like "windows" or "linux", not "wince", "winnt" etc.</p>
  
  <p>So far, I have to leads: PHP_OS and uname(), the later being more reliable than the earlier  (PHP_OS says what OS PHP was built on - according to documentation).</p>