Any time I reinstall Windows on my desktop machine, there are 2 programs that go on before anything else: anti-virus and a personal firewall. However, on my MacBook, I have no anti-virus installed, and the firewall comes pre-installed.
Following the initial release of Leopard, there were some concerns regarding the efficiency of the firewall. The configuration utility provided with Leopard, or for that matter, Tiger, is not great for power users. You can use the command line to view and edit the firewall rules, but it’s not the most intuitive way to do it. Enter WaterRoof. Available for both Tiger and Leopard, this handy tool allows you to apply either pre-built rule-sets or to create your own.
As well as allowing editing of rules, WaterRoof also provides access to the firewall logs, either graphically or the raw statistics. If you’re new to Mac OS and want more control over the inbuilt firewall, the WaterRoof is worth having.