Sanewall is a firewall builder for Linux that uses an elegant language abstracted to just the right level. This makes it powerful and easy to use, audit, and understand. It allows you to create very readable configurations even for complex stateful firewalls. Sanewall can be used for almost any purpose, including control of any number of internal/external/virtual interfaces, control of any combination of routed traffic, setting up DMZ routers and servers, all kinds of NAT, providing strong protection (flooding, spoofing, etc.), transparent caches, source MAC verification, blacklists, and whitelists. Newer versions abstract the differences between IPv4 and IPv6, allowing you to define a common set of rules for both, while permitting specific rules for each as you need. Sanewall is a fork of FireHOL and can make use of existing FireHOL configurations.
txtorcon is a Twisted-based asynchronous Tor control protocol implementation. Twisted is an event-driven networking engine written in Python, and Tor is an onion-routing network designed to improve people’s privacy and security on the Internet. It includes unit-tests with 96%+ coverage, multiple examples, and documentation. There are abstractions to track Tor configuration and state (circuits, streams), launch private instances, support Hidden Service, and more.
URLCrazy checks for mistyped domain names of websites. It can detect typo domain squatters and help protect your domain security by identifying domain names to preemptively register. It generates 15 types of typos, including bitflipped domains, knows over 8,000 common misspellings and over 450 homophones, supports multiple keyboard layouts, checks whether a typo is a valid domain, and can test whether domain typos are in use and estimate the popularity of a typo.
QuintoLabs Content Security is an ICAP server/URL rewriter that integrates with your Squid Proxy Server to provides rich content filtering functionality, sanitizing Internet traffic passing into internal enterprise networks. It may be used to block illegal or potentially malicious file downloads, remove annoying advertisements, prevent access to various categories of Web sites, and block resources with explicit content.