deskmenu software package provides A root menu for X11 window managers, you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install deskmenu
deskmenu is installed in your system.
Make ensure the deskmenu package were installed using the commands given below,
$ sudo dpkg-query -l | grep deskmenu *
You will get with deskmenu package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | X Window System software |
| Package | deskmenu |
| Version | 1.4.5 |
| Description | A root menu for X11 window managers |
| Sub Section | X142 |