Hm! This one is new to me – seems interesting.
The pfSense® project is a free, open source customized distribution of FreeBSD specifically tailored for use as a firewall and router that is entirely managed via web interface. In addition to being a powerful, flexible firewalling and routing platform, it includes a long list of related features and a package system allowing further expandability without adding bloat and potential security vulnerabilities to the base distribution. The pfSense project has become a fairly popular project with more than 1 million downloads since its inception, and proven in countless installations ranging from small home networks protecting a single computer to large corporations, universities and other organizations protecting thousands of network devices.
This project started in 2004 as a fork of the m0n0wall project, but focused towards full PC installations rather than the embedded hardware focus of m0n0wall. We also offer an embedded image for Compact Flash based installations. The two projects have since diverged significantly.
We’ve steadily grown to become one of the most widely used network firewalls in the world, with in excess of 200,000 known live installs as of December 2013.
[From About pfSense – pfsense.org]