In the X Window System, an X session manager is a session management program, a program that can save and restore the current state of a set of running applications, including window manager. Overview From the point of view of an X session manager, a session is a “state of the desktop” at a given time: a set of windows with their current content. More precisely, a session is the set of clients managing these windows or related to them and the information that allows these applications to restore the condition of these windows if required. The most recognizable effect of using a session manager is the possibility of logging out from an interactive session and then finding exactly the same windows in the same state when logging in again. For this to work, the session manager program stores the names of applications that are running at logout and starts them again at login. Moreover, for the state of the applications to be restored as well (which is needed to restore the content of windows), the applications must be able to save their state of execution upon request from the session manager and load it back when started again. In general, a session can be saved or loaded at any time, even if the user is not logging in or out. It is also possible to save a number of different sessions and loading one of them at user's choice. Sessions can also be specified by providing the list of applications that compose the session. As a result, the user has the possibility of saving a set of different sessions, either by storing the state of execution of the currently running applications or by explicitly listing the applications that compose a session. This way, the user can later decide to load a given session. XSMP Protocol In order for a session to include the state of an application, the application must be able to store and load its current state when session manager request to do so (usually on user login or logout). A protocol named X Session Management Protocol (XSMP) specifies how applications and session managers interact. The XSMP message format is the same as Interactive Connectivity Establishment (ICE) message format. Of particular importance is that the window manager is able to communicate with the session manager, as the window manager is responsible for the placement of windows and