xdg-utils

This version of xdg-utils contains the following commands:
xdg-desktop-menu: command line tool for (un)installing desktop menu items
xdg-desktop-icon: command line tool for (un)installing icons to the desktop
xdg-mime: command line tool for querying information about file type handling and adding descriptions for new file types
xdg-icon-resource: command line tool for (un)installing icon resources
xdg-open: opens a file or URL in the user's preferred application
xdg-email: command line tool for sending mail using the user's preferred e-mail composer
xdg-screensaver: command line tool for controlling the screensaver

ttp://portland.freedesktop.org/xdg-utils-1.0/

これらはインストールされてるんだな。（役に立つ人には役に立ちそう）
Xfce、xfwmとは別にxdgというキーワードにフォーカスすることになりそうだ。