SINGLE LOGIN PROCEDURE FOR ACCESSING SOCIAL NETWORK INFORMATION ACROSS MULTIPLE EXTERNAL SYSTEMS

A social networking system contains information describing users of the social network and various connections among the users. A user can access multiple external systems that communicate with the social networking system to access information about the users of the social networking system. Login status of the user account on the social networking system is maintained. If the login status of the user account on the social networking system indicates that the user is not logged in, the user is required to provide authentication information. If the login status of the user account indicates that the user is logged in, social network information is provided to the user via an external system, subject to the privacy settings of users of the social networking system. If the user logs out from an external system, the user is also logged out from the social networking system.