Firewalls are not something that Mac users usually have to concern themselves with but as Macs grow in popularity, this will change somewhat.
Adding a Firewall adds an extra layer of protection to your machine, which should prevent anything malicious from affecting your Mac. Doorstop X has been designed specifically with Leopard in mind and features an easy-to-use interface that even those new to firewalls shouldn't find problematic. Unless you're a system admin expert though, you will need to consult the instructions on more than one occasion.
Fortunately, the interface of Doorstop X makes this extremely easy with an 'Ebook' button on every Window pane that takes you to the appropriate part of the instruction manual. Each element that's protected by Doorstop X is listed clearly down the left-hand window pane. This can include anything from iTunes and iPhoto music sharing to iChat and Remote Login services. To edit any of the settings, simply select the service and click 'Edit'.
If the service you want to protect isn't on there, you can create it by clicking 'New' and Doorstop X reveals the elements and features that you can protect. You can easily toggle Doorstop on and off by clicking the 'Start' and 'Stop' button at the top. Note that some people have complained that it stopped applications like Skype working although I experienced no such problems and maybe this illustrates how important it is to understand how to configure ports properly. Probably the best advice is to follow the setup wizard if you're unsure rather than try and configure Doorstop X manually.
Doorstop X is a fast, highly configurable, and easy-to-understand firewall. You'll still need to spend some time understanding how to configure ports and understand firewall jargon but Doorstop X makes this as easily accessible as possible.
