Which of the following is commonly used for federated identity management across multiple organizations?

SAML is an XML-based open standard that enables identity providers to securely pass authorization credentials to service providers, facilitating single sign-on (SSO) and federated identity across distinct security domains or organizations. This allows users to authenticate once with their home organization's identity provider and gain access to services hosted by other organizations without re-authenticating.

Active Directory is a directory service used for managing identities and resources primarily within a single Windows domain or forest, not as a direct protocol for federated identity management across independent organizations.

Kerberos is a network authentication protocol designed to secure authentication within a single trusted realm, not for federated identity across disparate organizations.

LDAP is an application protocol for querying and modifying directory services, not an identity federation protocol for cross-organizational single sign-on.