I've been a hard-core Untangle fan for several years now, but I recently wanted to explore other firewall options. Being wrapped around a commercial product, Untangle charges money for its high-end features. However, I figured since most all those features are covered by the open source community, there must be non-commercial options out there. I began my hunt for the best free firewall. I scoured the internet, downloading any and all offerings from 2 principal types of entities: 1. companies with an open source community branch or free non-trial version, and 2. open source community projects ("free as in speech" or free software / paid support biz models).
I tried just about every ISO I could get my hands on. I thought I had my work cut out for me since I found far more of them than I had expected. But I did notice some common themes--several of them seemed to share common ancestors / packages (e.g. Squid, Debian, FreeBSD, etc). Here's a list of what I found along with my impressions.
Read more: The Hunt For the Ultimate Free Open Source Firewall Distro