Some time ago I came over pfSense in a project and did some review of it. pfSense is a FreeBSD based firewall with many features and an easy to use web based interface. It works nicely in virtual environments like VMware and it’s installation is quite easy.
Within a few minutes you have a easy to manage firewall with many upper class features like VPN (IPSec, OpenVPN, PPTP), Monitoring, NAT, directory service connectors and much more. With it’s included plugin system you can extend the main functionality for example with a squid proxy.
If you need a firewall solution which has support it’s no problem there is also commercial support available.
For information about the development process in the pfSense team you may have look at the bugtracker.