I've shown previously how to add an item to Ubuntu's (or any Gnome desktop) menu, but that post only showed how to edit the menu for a single user. In this post I'll show how to add an item to the menu so it shows up for every user on the system. I'm going to add a special icon to launch a terminal window from the Applications->Accessories menu in Ubuntu. You can find more info at the GNOME Documentation Library.

Create a Desktop Launcher

Right click on the Desktop and select Create Launcher. Enter a name, I'll call mine Tux Term. Enter the command, in my case it's gnome-terminal.

Click OK. You'll now have an icon for Tux Term on your desktop.

Edit the Launcher File

You need to add a line to the launcher file that you just created. Double click on your new icon to launch a terminal for the next step.

Add the following line to the end of the file and save it.

Categories=Utility

The Utility category will make the menu item show up in Applications->Accessories. For the full list of categories, see the GNOME Menu spec for Registered Categories.

Copy the Launcher File to the System Directory

Enter the following terminal command:

You should get something that looks like

Your output might be slightly different. This means that I can put a launcher file in any of the three directories listed. If your system doesn't list a directory, then put your file in /usr/share/applications/. In my case, /usr/local/share/applications/ seems like the best location. You need to be the root user to copy the file to the system directory.  It's easiest to use the terminal.

Edit the System Menu

Check to see that the $XDG_CONFIG_DIRS variable is set.

If you got output from that, then edit the menu file with:

If your echo command did not yield a result, then edit the /etc/xdg/menus/applications.menu file.

Find the following section of the file and add the lines in bold.

<Directory>Accessories.directory</Directory>
<Include>
   <And>
   <Filename>Tux Term.desktop</Filename>
   </And>
   <And>
   <Category>Utility</Category>

Save the file and exit the text editor.

You're new Tux Term launcher will now show up in the Applications->Accessories menu. You can use the User Switcher to log in as a different user and verify that the menu item shows up there as well.