You can make a simple MSN control (which users can login), web authentication gateway (Horatio based), load balance (iproute2), traffic shape (QoS), simple packet filter and NAT redirects (DNAT), loadbalance and VPN gateway or roadwarrior and ...
chainssh is a shell script to smplify the ssh login via multiple sshgateways/firewallgateaways. e.g. connect from homehost via sshgateway to a clusternode with one command.
GTCop Professional Security Appliance aims to provide a powerful tool for satellite communications, with enhanced QoS and bandwidth controls. As derived from IPCop Firewall, it is a stable, secure, easy to configure and maintain GNU/Linux firewall box.