The DoorStop X Firewall

DoorStop X 2.4 is available for Mac OS X 10.5.8 or later and supports Lion (Mac OS X 10.7) . You can download a free, fully-functional 30-day evaluation version here. You can purchase DoorStop either individually or as part of the integrated DoorStop X Security Suite. DoorStop X 2.4 features include:

Easy-to-use main window with standard Mac OS X services built-in.
All TCP services protected by default.
Ability to tune protection on a service-by-service and address-by-address basis.
Protect services by name or port number(s).
Default protection setting which applies to all unspecified services.
Four protection modes: deny all, allow all, allow by address, deny by address.
Setup assistant to help you best secure your Mac's services.
Full logging of allowed and/or denied connections on a service-by-service basis. Integrated with our Who's There? Firewall Advisor to help you understand, analyze and react to access attempts.
Includes a built-in version of "Internet Security for Your Macintosh: A Guide for the Rest of Us," browsable on a service-by-service or section-by-section basis.
Includes direct access to and searching of our blog, isfym.com, blog, Twitter stream and Top 10 list, for information and advice on recent security issues.
"Locations" provide different protection settings in different environments.
Status menu item available at all times: confirm settings, easily switch Locations.
Optional protection and logging for UDP services and ports.
Automated log archiving.
Stealth mode.
Updated with newest service names and ports.

DoorStop was the first Macintosh firewall, for Mac OS 8.1 in 1998. Open Door has been shipping security products since that time. We know how to help you make your Macintosh secure on the Internet.