For those who have both KDE and GNOME installed...., or XFCE with either or both.
Just because GNOME apps are not in the KDE menu, doesn't mean you can't use them. Same goes for KDE apps while using GNOME.
Do, in a term: sudo apt-get install menu menu-xdg
...then in a terminal do: sudo update-menus (The "sudo update-menus" is just for the first iime after installation of those menu utilities to activate their function in the system...)
then update-menus (which is the command to use to update the Debian entry menu after the installation of new applications. The regular KDE and GNOME menu systems update automatically for the respective system applications.)
In the KDE system, you should see a new entry in your menu tree under "Other" or under "Debian" or something else.... This will be ALL the applications in your system arranged alphabetically.
In Gnome, you have to open "Menu Layout" under "System" > "Preferences" (panel menu)... then check the "Debian" checkbox.
Under XFCE, after an update-menus, you should see all system apps under a "Debian" or "Other" entry.
NOTE: KDE uses kdesu to launch apps (kdesu app-name) in admin mode and GNOME uses gksudo (gksudo name-of-app) to launch its apps in "su" mode.