"A curated list of awesome honeypots, tools, components and much more. The list is divided into categories such as web, services, and others, focusing on open source projects."
"firewall builder for Linux ... easy to use, audit, and understand. It allows you to create very readable configurations even for complex stateful firewalls. ... Sanewall is a fork of FireHOL."
Configuration changes unfortunately require re-compilation, otherwise neat.
German abstract: http://linuxwochenende2010.luga.at/12/