We have a network of XP machines, with a 2003 Standard DC running in 2000 mode. We really only need Windows for an app that uses SQL Server.
Is it feasible to get a Linux or BSD server going as an AD DC/fileshare/DNS for these XP machines, and get 2012 Essentials or even Foundation going just for the SQL Server? Is there a way to get them to play nicely? If so which Linux or BSD would you recommend for this purpose and why?