Firewall Builder is multi-platform firewall configuration and management tool. It consists of a GUI and set of policy compilers for various firewall platforms. (GPL)
Linux - FreeBSD
Lynis is an open source security auditing tool. Its main goal is to audit and harden Unix and Linux based systems. It scans the system by performing many security control checks. (GPL)
Linux - FreeBSD - MAC OS X
NSnitch is a DNS server which records the IP address of requests made against it and then makes that IP available via a JSON API. It also provides lookups for Tor Node membership, DNS blacklist status and Geo data. (Apache)
Linux - Windows
The Shoreline Firewall, more commonly known as “Shorewall”, is high-level tool for configuring Netfilter. You describe your firewall/gateway requirements using entries in a set of configuration files. (GPL)
Linux
5 applications