Linux replacement for Windows Domain Server

[Steve Kilbride]

I've been using Samba as a PDC for a while now.  Rock solid.  But if 
you need Active Directory, then you'll have to go with version 4 and 
hope it works well for you.  I'm a believer in minimalism - if I 
don't NEED it, I'm not going to implement it.  I also have a Win2003 
Server (which, of course, supports AD) but since I don't need it, I 
chose not to implement it.  As a result, my Win2003 server has been 
almost as reliable as the Linux box.