title: Get users OS and version number
body: <p>I've spent a day on and off Googeling for this; no luck so far.</p>
  
  <p>How can I get the users OS and version. Mine would me Mac OS X 10.6.4, the spare PC in the office would be Windows XP SP3. You see what I'm getting at.</p>
  
  <p>I've seen a million and one methods to get the users platform alone, just not the version.</p>
  
  <p>JS would be ideal, but a server-side (PHP) solution is OK too.</p>