Bastion-firewall project
bgSEC, bastion-firewall, bastionfirewall, UNbeatABLE Linux, UNbeatABLE CD
http://bastionfirewall.sourceforge.net/

Firewall Appliance Defined
Firewall Servers is a manufacturer of high-density internet appliances and products, including: network security software & appliances, firewall software & appliances, content filtering software.
http://www.firewall-servers.com/what_are_firewall_servers.html

Dolphinwall. The Dynamic Firewall
Firewall,DolphinWall
http://www.dolphinwall.com/

The Firewall Toolkit (FWTK)
Learn how to build/maintain inexpensive firewall and security solutions
http://www.fwtk.org/

APF Firewall
Our goal as a Privacy/Internet Security company is to power the future of Privacy/Internet Security. We shall do this through advanced technology and fresh ideas by a diverse staff which will in turn allow us to develop software, hardware and services to suit customer needs into the future.
http://www.rfxnetworks.com/apf.php

Gibraltar Firewall
Gibraltar Firewall. Professional Corporate Security Gateways. UTM-Appliance. Router, Firewall, Proxy-Server, VPN-Gateway, Antivirus, Antispam.
http://www.gibraltar.at/index.php?home_ger

Securepoint Firewall Server
Securepoint UTM Appliance, Firewall, VPN, Contentfilter, Virenscanner, IDS, SIP, Proxy, VoIP, QoS, Netzwerk-Firewall, VPN Server, PC-Firewall, Personal Firewall, Security, Network, Netzwerk, VPN, E-Business, E-Commerce, Antispam, Anti-Spam, Content-Filter, Antivirus, Virenscanner, Virus Scanner
http://www.securepoint.cc/

Wolverine Firewall and VPN Server
Requiring minimal hardware this firewall and VPN gateway, has stateful packet inspection, IPSEC and PPTP VPN services, with remote web based administration. There are also embedded versions sold as firewall appliances.
http://www.coyotelinux.com/

Vicomsoft Firewall Q&A
A whitepaper on relevant firewall questions and answers. The knowledge of this subject relates to firewalls in general use, and stems from NAT and proxy firewall technology experience. Welcomes feedback and comments from any readers on the usefulness or content.
http://www.vicomsoft.com/knowledge/reference/firewalls1.html

Telco Tech GmbH
Miete des Firewall-Equipments und Outsourcing des Firewall-Managements. Die Firma überlässt und betreibt Firewall-Systeme zum Schutz von Kundennetzen vor Angriffen aus dem Internet. Optional kann ein Virenschutz implementiert werden.
http://www.managed-security.de/