NetBSD Firewall Solution
Of course Linux is not the only player in the open source game. Many people seem to overlook the *BSD variants which all have there advantages. One such variant is NetBSD and the NetBSD Firewall solution has, you guessed it, developed a slimmed down version of NetBSD to use as a firewall. If you have an old 486 laying around (who doesn’t), then you might wanna give it a try.