EnGarde Secure Linux is the world’s first Open Source security platform. The launch includes the introduction of Guardian Digital Health Center, the proactive approach towards monitoring your system hardware. FWKNOP and PSAD as covered in “Linux Firewalls” by Michael Rash are new tools for the best in secure servers. The new tools include a collection of three lightweight system daemons that analyze iptables log messages to detect port scans and suspicious traffic. They also include an authorization scheme called Single Packet Authorization (SPA)”]
Source: https://www.darkreading.com/attacks-breaches/new-version-of-engarde-secure-linux-released