No answer on that one, However Mac OS X also includes a built in firewall. On the configuration angle, the Microsoft ICF (Internet Connection Firewall) blocks everything by default. Scott C. McGrath On Thu, 14 Aug 2003, John Neiberger wrote:
Sean Donelan <sean@donelan.com> 8/14/03 8:29:07 AM >>> John Markoff reports in the New York Times that Microsoft plans to change how it ships Windows XP due to the worm. In the future Microsoft will ship both business and consumer verisons of Windows XP with the included firewall enabled by default.
[Veering further off-topic]
Hmm...I didn't even know XP had a built-in firewall. Any bets on how long it is before other companies with software firewall products bring suit against Microsoft for bundling a firewall in the OS? --