XORP 1.0 Released
Mark Handley writes "XORP is the eXtensible Open Router
Platform - an open-source router software stack for FreeBSD and Linux.
It's designed from scratch to be extensible, so you can write your own
router applications that play nicely with the existing routing
protocols. We just released XORP 1.0! There's also a Live CD if you want to try
it out without reinstalling your machine. More details in this CNET article."
But this is good for colleges and other places where the concentration of "guys who can stop by and fix the router" is high. Also not to mention the tinfoil factor of a readonly-livecd router (but does it have remote logging).
Quidquid latine dictum sit, altum videtur
There's also Quagga, a fork of the GNU Zebra (thanks Kunihiro), which is further along, more mature, in much wider use than XORP (I've not heard of anyone actually using XORP in production, while GNU Zebra and Quagga most definitely are) and, most importantly, not written in C++ ;).
NB: I'm biased.
I use Friend/Foe + mod-point modifiers as a karma/reputation system.