xsm is a session manager for the X Session Management Protocol.
A session is a group of applications, each of which has a particular
state. Applications can automatically become part of the session.
Within a session, you can perform a "checkpoint" to save application
state, or a "shutdown" to save state and exit the session. When
you log back in to the system, you can load a specific session,
and you can delete sessions you no longer want to keep.
