Microsoft released a beta code, currently in an early-stage, and internally called as “Next Generation Active Directory (NGAD),” that’ll define the next evolution of directories. It's a modular add-on that is built on a database and designed to add querying capabilities and performance never before possible in a directory. NGAD, however, isn’t a replacement for Active Directory but a "clip-on" that provides developers a single programming API for building access controls into applications that can run either internally, on devices or on Microsoft's Azure cloud operating system. Users’ll not have to alter their existing directories but’ll have option to replicate data to NGAD instances. NGAD stores directory data in an SQL-based database and utilizes its table structure and query capabilities to express claims about users such as "I am over 21" or "Henry is my manager." To ensure security, each claim is signed by an issuing source, such as a company, and the signatures stay with the claim no matter where it is stored.
More info: Network World