Both Linux and FreeBSD are built on strong networking stacks, and both make first-rate firewalls and routers. Many commercial products are based on these. This LinuxPlanet article looks at four open and free Firewall/Router projects: pfsense, m0n0wall, Endian, and SmoothWall.
“pfSense: 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 has low system requirements; 100 MHz Pentium CPU and 128 MBs of RAM. The Live CD requires a CD-ROM drive and a USB flash drive or floppy drive for storing the configuration file. The hard drive installation requires a CD-ROM for the initial installation and at least 1 GB hard drive. The embedded version requires a serial port for console and at least a 128 MB Compact Flash card.”