I'm currently using this execrable collection of shell scripts to manage a WISP of around 2,000 clients. I have a feeling it could all be done in a single line of Perl, and would be delighted to see such a thing.

It's GPL'd, so feel free to have a go at it - I'd appreciate any feedback.

It relies on a linux box with a 2.4+ kernel, patched for htb, sitting inline between your uplink and your clients. Authentication is done by MAC address using iptables - clients may be given a specified IP address for client servers, or they may be created with no associated IP address (good for DHCP).

You will need a good understanding of iptables, tc/htb scheduling, fresh pants and a stiff drink to get this working.

Documentation:
Readme.txt

Sourceforge project page:
http://sourceforge.net/projects/yabmas/