FreeBSDShield is a DShield.org reporting client for FreeBSD and the ipfw firewall. It allows you to report attempted security breaches to the DShield cooperative firewall logging effort, which in turn helps the Internet Storm Center (and netizens at large) track trends in network security and catch emerging vulnerabilities.
The Subukan Sensor is a complete Network Intrusion Detection System (NIDS) platform. It is not simply an application one can install on an existing operating system. Rather, Subukan is a total software solution including both an operating system and a unique compilation of security tools. It is based on a single file image or firmware that transforms almost any hardware equipment into a fully functional NIDS appliance. Appliance- based technology simplifies administration and provides the capability for remote upgrades.