CacheGuard Gateway is a UTM, a WAF, and a QoS management appliance.
Firewall log analyzer
HTTP proxy to block ads and customize webpages
Next Generation Open Source Firewall
Anti Spam SMTP Gateway
Web application firewall in C language uses libevent
A powerful network security tool, easy, safe and totally free.
PeerGuardian - a privacy oriented firewall application
a secure, open source OS for use inside USEagency facilities