QuIDScor is an Open Source project demonstrating the value in correlating information between Intrusion Detection Systems (such as Snort) and vulnerability assessment and management platforms such as QualysGuard.
Open-source GPL rootkit scanner for Unix-like systems. Scans for rootkits, trojans, backdoors and local exploits. Tests include scanning of plaintext and binary files for MD5 hash comparisons, default rootkit files, binary permissions, suspect LKM/KLD...
Shadow is an intrusion-detection system from the Naval Surface Warfare Center, shows promise in detecting previously unknown attacks for which no known detection signatures exist.
An intrusion protection system in the form of a bash shell script that is designed to make the installation of Snort in inline mode on Fedora or Debian as easy as possible.
A configurable web-base administration console written in PHP which can remotely manage, control, and monitor multiple Snort based Intrusion Detection System sensors.
Systrace enforces system call policies for applications by interactively constraining the application's access to the system (*bsd and Linux). Systrace is able to monitor daemons on remote machines and generate warnings at a central location.