Security
Shorewall - iptables Firewall builder	Clam AntiVirus
Check Point FireWall-1	Symantec AntiVirus Corporate Edition
iptables - Linux based Firewall	TrendMicro ServerProtect for Microsoft Windows/Novell NetWare
Prelude Hybrid IDS	MailScanner - free Anti-Virus and Anti-Spam Filter
Snort - The Open Source Network Intrusion Detection System	iHateSpam