The pfSense project is a free network firewall distribution, based on the FreeBSD operating system with a custom kernel and including third party free software packages for additional functionality. Through this package system pfSense software is able to provide most of the functionality of common commercial firewalls, and many times more. It has successfully replaced every big name commercial firewall you can imagine in numerous installations around the world, including Check Point, Cisco PIX, Cisco ASA, Juniper, Sonicwall, Netgear, Watchguard, Astaro, and more.
pfSense software includes a web interface for the configuration of all included components. Unlike some similar GNU/Linux-based firewall distributions, there is no need for any UNIX knowledge, no need to use the command line for anything, and no need to ever manually edit any rule sets. In fact, the majority of pfSense users have never installed or used a stock FreeBSD system. Users familiar with commercial firewalls catch on to the web interface quickly, though there can be a learning curve for users not familiar with commercial-grade firewalls.