TACACS+ server recommendations?

[Bryan Holloway <bryan () shout net>]

Ah, the good old days when I could download the latest tac_plus code 
from the Cisco FTP site, compile it, and off I go.

But I digress.

Curious if there are any operators out there that have a good 
recommendation on a lightweight TACACS+ server for ~200 NEs and 
access-control for 20-30 folks. Nothing too special, but some sort of 
simple command-control auth would be nice.

Open-source is fine ... we've been looking at commercial options, but 
they're all pretty pricey and have way more features than we need.

Thank you all in advance!

                - bryan