Just by adding a few extra fields to a users's profile using "Console-1" (ie UID GID, home directory, shell etc) you can use this for authentication.

It Works quite well - if you can run some form of caching (eg nscd) or a more primitive way - eg a startup script that temporary adds those users to the /etc/passwd file.(else the server takes a hammering!!)

We use it on our network and I must admit it works WELL!

I havent tried it with AD but will be doing some tests soon on it.

For Mandrake 9.1 I've created a GUI tool that eases the setup of the clients.

This will be released soon (under GPL).