I don't know much about Directory server or Windows Active Directory, I just wan't know the possibility of having a Windows Active directory and a Directory Server(say, Redhat DS or Fedora Directory Server) inter-operate.
I was checking at the Redhat Directory server, Windows Sync which lets Directory server to synchronize the user and group attributes from AD and handle authentication. I want to know if it is possible for the directory server to handle the group policies, GPO updates etc., and can Directory Server be used as a source for SSO ?
What's the point of even having AD then? SAMBA 4 supposedly has full GPO support, but you'd be hard pressed to find many admins jumping to it at organizations with more than a handful of computers. I don't know of any way other than running AD (supported) or run SAMBA 4 (unsupported).
It's all just Kerberos nowadays, so as long as your mystery application supports it, sure - but the harder part is getting a Windows client to get a Kerberos ticket and successfully negotiate the logon process from a non-AD (or non SAMBA) directory server. You really can't without a ton of unsupported hackery as far as I know.
What's the bottom line? Just use AD for your Windows clients and either use AD for your *nix, or keep your *nix directory server in sync with an identity management solution like Tivoli or FIM.