fireBwall
Homepage
http://firebwall.com/index.php
Wilders discussion here.
fireBwall is a personal Windows firewall which allows for modular network access. This makes fireBwall more like a network swiss army knife than just your usual firewall. Modules can be developed in any language supporting .NET 2.0. We have many modules already built in, so new users can see the potential of what we can do. In case you didn't notice, fireBwall is a free firewall, and in our opinion, could be the best firewall. Microsoft Windows Security could be on par with some of the more hardened *nixes.
fireBwall is developed in C# and .Net 2.0 is required for fireBwall to run.
Homepage
http://firebwall.com/index.php
Wilders discussion here.