Security Onion is a Linux distro for IDS (Intrusion Detection) and NSM (Network Security Monitoring). It's based on Ubuntu and contains Snort, Suricata, Bro, Sguil, Squert, Snorby, ELSA, Xplico, NetworkMiner, and many other security tools. The easy-to-use Setup wizard allows you to build an army of distributed sensors for your enterprise in minutes!