The pfSense operating system is a free network firewall distribution, based on the FreeBSD operating system with a custom kernel and sporting both free and paid third party software packages for additional functionality. pFSense firewalls are able to provide the same functionality or even more than commonly available commercial firewalls, without any of the hidden limitations or cost. It has successfully replaced every big name commercially firewall you can imagine in numerous installations around the world, including Check Point, Cisco PIX, Cisco ASA, Juniper, Sonicwall, Netgear, Watchguard, Astaro, and more.
The pFSense distro when installed includes a web interface for the configuration of all the firewall’s modules. There is no need for any UNIX or Linux knowledge, knowledge of command line for anything or even knowing how to manually edit rule sets. Bare in mind that knowing these won’t hurt and would make you a God amoung men. Users familiar with commercial firewalls can catch on to the web interface very quickly, all though there can be a learning curve for users who are not familiar.