Question re: OS X Server and windows clients.

I have been hunting high and low and cannot seem to find an answer.

I am going to be moving my home network over to Mac this year and would like to setup a client / server environment instead of having a bunch of single user machines zooming around. I want to have clients log in to the server and use directory services for management of file-print services. Once I have everyone up I may deploy more services.

My first step is to get a file-print server. I could of course do this with just about anything with shared drives but that's not what I am going for. I know OS X Server can be integrated to a domain but I don't have a domain, does OS X Server have the ability to emulate it's own Active Directory or Domain controller or perhaps an Apple specific equivelent?

I want to use a Mac Mini with OS X Server (Leopard or Snow Leopard) have windows XP Clients log in to it.

I have tinkered with some Ubuntu but I'd like everything to be one platform / distribution. Any insight would be helpful.

Thanks.

OS X server utilizes Open Directory vs Active Directory (windows).

If you want one platform why are you looking to have XP authenticate to OS X server?