Communications between social networks are enabled via authentication that provides single-sign-on (SSO) authentication of users such as individual users or social networks or social network services that desire access to network resources on a particular social network. The particular network requests authentication of the requesting user(s), and based on an authentication result the particular network provides or denies access to the resources. A social network services database maintains a listing of resources of different social networks, that a user can search to determine where to find resources on other networks. The user can then query the social networks hosting those resources or their social network services for access, and the networks or services can authenticate the user before granting access according to any conditions that the hosting social networks or social network services may choose to apply.