Page "Active Directory" Paragraph 5

Active Directory was previewed in 1999, released first with Windows NT server.

Then Windows 2000 Server edition, and revised to extend functionality and improve administration in Windows Server 2003.

Additional improvements were made in Windows Server 2003 R2, Windows Server 2008 and Windows Server 2008 R2, and with the release of the latter the domain controller role was renamed Active Directory Domain Services.