A network security analysis and monitoring toolkit Linux distribution.
Free UTM appliance: firewall, VPN, WAF and antivirus in one ISO.
Anti Spam SMTP Gateway
The box to keep the Internet under your control
Xplico is a Network Forensic Analysis Tool (NFAT)
PotHead
Open Source SIEM
a secure, open source OS for use inside USEagency facilities
A flexible, extendable content filter