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.
iptables-bash_completion provides programmable completion for the iptables and ip6tables programs. iptables options are shown only if they are valid at the current context. It supports completion of options, matches, and targets, and dynamic retrieval of data from the system, including chains, set names, interfaces, and hostnames. Environment variables allow completion options to be tuned. IP and MAC addresses can be supplied using a file.
Libporty provides a higher level API for some commonly used library functions such as sockets, date/time, file system access, background processes, and asynchronous DNS resolving. Libporty is configured using scconfig and the API is guaranteed to work the same way on all supported systems. An application that exclusively uses the libporty API will not require autotools/scconfig for porting. Libporty has been tested on Linux, Windows, Mac OS X, multiple BSD variants, Minix, OpenSolaris, and some ancient Unix systems.
xllmnrd is an IPv6 LLMNR responder daemon (primarily for GNU/Linux operating systems). It allows Microsoft Windows clients to get the IPv6 address of a server on the same local network without any DNS configuration and effectively complements IPv4-only NetBIOS name resolution provided by Samba.