This version was released after Windows Server 2008 R2 but as a separate installation (download via web). All other versions came as part of the operating system. Before version 2.0, it was supported to use AD LDS as the authentication store. This means users can authenticate with AD LDS similar to AD. With version 2.0, it no longer supports LDS to act as the account store. It can work as the attribute store, which can store AD FS data but it cannot be used for authentication. AD FS 2.0 also supports a parent-child domain environment, so users in child domain can use AD FS in another domain for the federation. It reduces the management overhead. It also improved support for federation trusts with the use of industry-standard metadata formats. It allows organizations to create trust between federation partners quickly. Systems that run with version 1.x can have an in-place upgrade to 2.0 (if still trust).