4 Linux and BSD Firewall/Router Projects pfsense and m0n0wall
Here we'll look at four different firewall/router projects from the open source community:
pfSense is a customized distribution of FreeBSD. It actually started in 2004 as a fork of the m0n0wallproject. However, it concentrates more towards full PC installations, where m0n0wall is more towards embedded hardware.
pfSense can be considered as a popular package, as it has more than 1 million downloads. It can be used in homes or in large corporations and organizations. It's available as a Live CD, hard drive installation, or embedded.
pfSense, of course, includes a powerful firewall, including the ability to filter based upon the passively detected operating system.