-gdm-binary-+-gdm-simple-slav-+-Xorg
            |                 |-gdm-session-wor
            |                 |-gnome-session-+-gdm-simple-gree---{gdm-simple-gre}
            |                 |               |-gnome-power-man---{gnome-power-ma}
            |                 |               |-metacity---{metacity}
            |                 |               `-2*[{gnome-session}]
            |                 `-{gdm-simple-sla}
            `-{gdm-binary}