DoorStop X ($50) is designed to be used instead of the built in Mac OS firewall, eliminating Apple's all-or-nothing approach. Tuned for mobility, DoorStop X lets you define "locations", which provide different tiers of protection based on the type of network (ex. home, work, or public). Who's There? Firewall Advisor ($40) is designed to provide a specific, searchable log that can be used with Apple's built in protection or in conjunction with DoorStop X. As previously mentioned, Internet Security for your Macintosh: A Guide for the Rest of Us ($10) includes a new section for Leopard users, the eBook is written to interact with the Open Door Networks' internet security programs and online blog.