libnetfilter_cttimeout is an interface to Netfilter Connection Tracking timeouts. It provides a userspace library which provides a programming interface to the fine-grained connection tracking timeout infrastructure. With this library, you can create, update, and delete timeout policies which can be attached to traffic flows.
lsfw (list firewall) helps network administrators deal with firewalling on a huge network. It lists the firewalls rules applied between two points on the network. It uses the configuration of the network equipment and builds a (light) model of the network described by the equipment. This allows probing for access-list matching all over the network, doing routing and firewalling.
IPFire is a Linux firewall distribution that is built from source and comes with lots of additional features. It is easy to set up and administer. It features a firewall with stateful inspection, a content filtering engine, traffic control (QoS), VPN technology, and a lot of logging.