Session Manager for Xfce based DEs. Xfce allows to create different sessions and choose them at startup. Gnome is a default session manager for Gnome DE. Gnome has supported XSMP since v1.x. 2013 GNOME had intention to replace GNOME session manager XSMP with a D-Bus interface in version 2.24. It was eventually decided to combine both interfaces and provide an adapter (client) for legacy applications. At the time it wasn't feature-complete however, nor used by non GNOME applications. As of 2021 the codebase still includes X session manager clients. See also X Window System protocols and architecture X window manager References External links The X Session Management Protocol xsm manual page ksmserver, the KDE session manager ROX-Session, the ROX Desktop session manager X Window System