LK Port Knockd is a general purpose daemon for controlling connections to a specified port. It has multiple interfaces support, port filtering, unlimited passwords for a port, and logging. It can be started after or before main iptables rules are inserted. Rules can be modified to run on ipfw.
Snort2c attempts to be a improved version of snort2pf with some advantages, such as kqueue usage, pf table support, pf ioctl calls, modular design, daemon mode support, whitelist support, and syslog logging. It contains snort2c (a daemon) and mons2c (snort2c's table management tool).
SOFI is a complete firewall solution for OpenBSD. It is designed for use as an Internet gateway to share an Internet connection among several computers. It provides network address translation (a.k.a. IP masquerading), packet filtering, port forwarding, DNS service, DHCP service, VPN service, and traffic statistics.
DSM (Dedicated Server Manager) Standard is a solution for hosting companies and organizations who need to combine a Web server, mail server, DNS server, or a fully featured Web hosting environment. DSM Standard offers four levels of interface access: root user, reseller, site-owner, and mailuser.
Program Guard allows the user of a Linux workstation to specify which applications are allowed to make TCP/IP connections to the Internet. Application program names can be specified by listing them in a file (Static Mode) or by querying the user (Query Mode). In Query Mode, connection attempts by unknown programs result in a Program Guard dialog box being displayed. In addition to providing connection information, this gives the workstation user the option of allowing or blocking the program either for the current instance of the program or for all future instances. It consists of a daemon, a kernel module, and a GUI interface component and makes use of the Linux Netfilter interface.