this is more than just authentication/authorization. It also servers as a transparent bastion server tier, and allows you to do full historical auditing of inte

this is more than just authentication/authorization. It also servers as a transparent bastion server tier, and allows you to do full historical auditing of interactive sessions, on a highly available setup (if you set it up that way). You can rig a lot of this functionality up yourself, but there aren't a lot (or any) open source solutions out there that come as relatively complete turn-key packages.