Methods and apparatus for determining and maintaining user presence
information include capturing user presence data with an application
presence server. The application presence server can be configured to
update user presence data as a user initiates or exits an application.
Applications associated with user presence data are configured to query
an application proxy client concerning user presence data of a selected
user and, based on a returned user status, deliver, discard, or redirect
a message intended for the user. User presence data is stored in a user
presence repository and can be provided via Internet-based or other
connections to applications executed on external networks. User activity
status can be used to select or update user presence data. In some
examples, an application server of an external network is configured to
receive user presence data from the presence server.