OD as replacement for AD with win/linux clients

As I noted in the subject of this thread I am looking for information/help/manuals on using OpenDirectory as a [b]replacement[/b] for an ActiveDirectory system. All information I found so far talks only about integration of OD in an existing AD network but I want to scrap these Windows 2003 Server machines in favor of two XServes. B) The clients of the OD will be windows and linux clients. Has anyone done this or knows where to get information?