Network management and control with AAA (tacacs+ and in future radius) with some cluster facility - share critical information (active users, active devices) across a bundle of servers. CLI and Web control and telnet-like interface for external programs.
Sadly this doesn't compile under Linux. It is for FreeBSD and Solaris. My original longer review discussing it's merits and failings was blown away by an aggressive filter as junk possibly because I mentioned the company that invented the TACACS+ protocol by name. However my rating is for the product because it doesn't compile nor link for the more popular OS and took some effort before I realized this and not for sourceforge's filtering. And there is no such protocol as TACACS++, it's just TACACS+.