Fallback-gw is a little script to be called via cron that checks availibility of neighbor routers using ping and activates backup routing on ping failure. It can be used as a stupid replacement for BGP/OSPF in a multihomed environment. It has been tested on FreeBSD and on Linux with iproute2.
A garbage collector as a replacement for C malloc or C++ new.
A system to allow unattended reboots with an encrypted root file system.