Interesting new authentication/identity service/protocol/system spearheaded by Meebo. Allows all service providers to share the details of if a user has an account with them, and potentially share information about them as well.
#spec
Implementers’ Draft: XRDS-Simple 1.0 Draft 1
Implementers’ Draft: XRDS-Simple 1.0 Draft 1
“XRDS-Simple provides a format and workflow for the discovery of resources metadata, and other linked resources.”