Patent attributes
Real time availability data (free/busy data) is provided for potential meeting attendees and/or assets. An availability service is queried for availability data for one or more attendees and/or meeting assets. The availability service determines the identity of an electronic mailbox server on which is stored current real time calendaring data for the desired attendees and/or assets. The requested data is retrieved by the availability service from one or more mailbox servers having data for each attendee and/or asset. Potential attendees may set permissions on their respective availability data to restrict the amount and types of data that may be retrieved by a given data requester. Data queries and data responses may be structured according to the Extensible Markup Language (XML) and application programming interfaces (API) may be exposed for allowing requesting applications to efficiently call the availability service for availability data.