Can Visual Guard .Net be used to connect to web applications residing at different domains, using single sign on?

Yes it's possible to authenticate users belonging to several AD (even if they are not in the same forests) in using Visual Guard.

With ADFS you federate several Active Directory repositories belonging to distinct networks or companies. Administrators declare Windows accounts or Windows groups from these Active Directories in a central Visual Guard Repository. Then, the corresponding users can access the applications secured by the system. As a result, you get one central security system, although users are spread over several independent Windows domains.

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