Open Source Python Firewall Software for Linux

CacheGuard Gateway is a free and open-source Unified Threat Management (UTM) solution, a Web Application Firewall (WAF), and a Quality of Service (QoS) platform designed to optimize WAN traffic. To obtain a CacheGuard Gateway appliance, download CacheGuard-OS and install it on the bare-metal or virtual machine of your choice. It’s that simple and completely free. The UTM includes a firewall, web antivirus, VPN server, and a URL-filtering and SSL-inspection web proxy. The WAF operates in conjunction with a reverse proxy, web application load balancer, and SSL offloader, and is capable of blocking malicious requests as well as traffic from IP addresses with poor reputations. The QoS manager enables traffic shaping to prioritize critical network flows, load balance multiple WAN links, and cache web traffic.

MailCleaner Open Source Edition is now discontinued but will continue under the spamtagger project https://github.com/SpamTagger [antispam] MailCleaner is an anti-spam / anti-virus filter SMTP gateway with user and admin web interfaces, quarantine, multi-domains, multi-templates, multi-languages. Using Bayes, RBLs, Spamassassin, MailScanner, ClamAV. Based on Debian. Enterprise ready. MailCleaner is an anti spam gateway installed between your mail infrastructure and the Internet. It includes a complete GNU/Linux OS and a graphical web interface for user and administrative access. It comes in the form of virtual machine templates.. - fully compatible with any SMTP mail server (Exchange, Zimbra, O365,...)

A firewall is used to control access to services (eg proxy) depending on the time of day, the day and the hosts the requests come from -- as the need may arise in a school or university. A web interface delegates control of activation to authorized users.

Small but complete enviroment for building custom embedded system (x86 and other). Based on the gentoo system and uclibc-embedded project. Ideal for small hardware like WRAP or Soekris.

Solarwall is a web based toolset for manipulating Linux iptables. The goal is to provide modular framework for expansion.

fwgraph is an attempt to characterize and present network traffic including network devices, QoS, and iptables under Linux.