pfSense is a bigger badder fork of m0n0wall Its based on FreeBSD 6 rather than m0n0wall's FreeBSD 4 base.

pfSense also has support for more enterprise technologies, like firewall failover with CARP, traffic shaping, WAN load balancing or failover, captive portal, OpenVPN, etc.

m0n0wall's advantage is that it works fine on embedded hardware like the Soekris and in 64 MB ram, whereas pfSense requires a minimum of 128MB.

pfSense released version 1.2 in late February 2008.