Sguil
Sguil is a collection of free software components for Network [Security Monitoring] and event driven analysis of IDS alerts. The sguil client is written in Tcl/Tk and can be run on any operating system that supports these. Sguil integrates alert data from Snort, session data from SANCP, and full content data from a second instance of Snort running in packet logger mode.
Sguil is an implementation of a Network Security Monitoring system. NSM is defined as "collection, analysis, and escalation of indications and warnings to detect and respond to intrusions."
Sguil is released under the GPL 3.0.