Package: xfce4-session

/usr/bin/xfce4-session /usr/bin/xfce4-session-logout /usr/bin/xfce4-session-settings /usr/bin/xfce4-tips

You may install this package on CentOS with yum install xfce4-session

/usr/bin/startxfce4 /usr/bin/xfce4-session /usr/bin/xfce4-session-logout /usr/bin/xfce4-session-settings /usr/bin/xflock4

You may install this package on Debian with apt-get install xfce4-session