Apple has just released a beta version of the brand new Safari 4 browser. Safari 4 beta is available for both Mac OS X and Windows.
On Mac, Safari 4 identifies itself with the following user agent. The Intel Mac OS X 10_5_6 token represents the OS version the client is running, in this case Leopard.
Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_6; en-us) AppleWebKit/528.16 (KHTML, like Gecko) Version/4.0 Safari/528.16
The following one identifies Safari 4 on Windows. The Windows NT 5.1 token represents the version of Microsoft Windows OS the client is running, in this case Windows XP.
Mozilla/5.0 (Windows; U; Windows NT 5.1; it-IT) AppleWebKit/528.16 (KHTML, like Gecko) Version/4.0 Safari/528.16
The Safari version can be extracted from the Version/4.0 token, regardless of the operating system behind the browser. Even in Safari 4, the browser doesn't forsake the habit of injecting the cryptic AppleWebKit version in the final user agent. You can see it identified by the token AppleWebKit/528.16.