Windows 2000 Authorization Manager Runtime is a Windows 2000 Server version of the Windows Server 2003 Authorization Manager Role-Based Access Control (RBAC) API. Windows Server 2003 family operating systems introduced the Authorization Manager RBAC framework which includes the Authorization Manager API and Role-based MMC snap-in Administration UI (Authorization Manager Snap-in UI is only available on Windows Server 2003 family operating systems and on the Windows Server 2003 Administration Pack for Windows XP). The Authorization Manager API provides a simplified development model in which to manage flexible groups and business rules and store authorization policies. Storage in Active Directory requires the domain to be at Windows Server 2003 functional level. Using the Windows 2000 Authorization Manager Runtime you can build server applications to use the Authorization Manager Role-based access control model that run on Windows 2000 Server family operation systems.