How to install Unity Desktop on Ubuntu

Canonical developed Unity as a graphical shell for GNOME and used it as the default desktop environment for Ubuntu. Canonical has since stopped the development of Unity though UBports now maintains it.

Ubuntu Unity Remix is an Ubuntu variant with Unity as the default desktop environment. You can still install Unity if you're running the standard Ubuntu distribution or any other Ubuntu variance. This is because Unity Desktop packages are available in apt's default repository that you can install at the terminal.

1. Launch terminal.
2. Update apt's package list from the repositories.

   $ sudo apt update
   Hit:1 http://ports.ubuntu.com/ubuntu-ports jammy-security InRelease
   Hit:2 http://ports.ubuntu.com/ubuntu-ports jammy-proposed InRelease
   Hit:3 http://us.ports.ubuntu.com/ubuntu-ports jammy InRelease
   Hit:4 http://us.ports.ubuntu.com/ubuntu-ports jammy-updates InRelease
   Hit:5 http://us.ports.ubuntu.com/ubuntu-ports jammy-backports InRelease
   Reading package lists... Done
   Building dependency tree... Done
   Reading state information... Done
   All packages are up to date.

3. Upgrade installed packages using apt.

   $ sudo apt dist-upgrade --assume-yes
   Reading package lists... Done
   Building dependency tree... Done
   Reading state information... Done
   Calculating upgrade... Done
   0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

4. Install ubuntu-unity-desktop package using apt.

   $ sudo apt install --assume-yes ubuntu-unity-desktop
   Reading package lists... Done
   Building dependency tree... Done
   Reading state information... Done
   The following additional packages will be installed:
     a11y-profile-manager-indicator accountsservice-ubuntu-schemas
     activity-log-manager adium-theme-ubuntu bamfdaemon catdoc
     cinnamon-desktop-data cinnamon-l10n compiz compiz-core compiz-gnome
   ##### snipped
   0 upgraded, 417 newly installed, 0 to remove and 0 not upgraded.
   Need to get 244 MB of archives.
   After this operation, 681 MB of additional disk space will be used.
   ##### snipped

5. Select lightdm by using the arrow key, use the [TAB] key to reach the Ok button and press [ENTER].

   Use [TAB] key to navigate to the Ok button and press [ENTER] to start configuring LightDM if you're first presented with the following screen. You'll get this screen if you're using a low resolution monitor and/or not running terminal in full screen.

6. Wait for installation to finish.
7. Reboot your system.

   $ sudo reboot

8. Click on the Ubuntu icon to reveal the desktop environment selection panel.
9. Click on the Unity selection.
10. Key in your password and press enter to log in to your Unity desktop.