Not so long ago GNOME received an update. Firstly, the GTK4 library was switched to GTK4, and secondly, the principle of working with applications was changed. Therefore, a new numbering was decided: 3.38 is immediately followed by the 40th version.
Using Ubuntu 21.04 as an example, let's consider the innovations of GNOME 40, the peculiarities of the shell on this distribution, as well as how to install Gnome 40 in Ubuntu.
Note that the version of the shell under consideration is not official and is located in a custom PPA repository. Therefore, it is better to abandon the idea of installing the shell on the main system, for this purpose, use better reservers. A virtual machine or a system on a second disk is optimal.
To install GNOME 40 on Ubuntu 21.04, you should first add a repository and update the list of packages:
$ sudo add-apt-repository ppa:shemgp/gnome-40
$ sudo apt update
Now you can proceed to install the shell itself and related utilities, after which you should update the current packages:
$ sudo apt install mutter gnome-session gnome-shell
$ sudo apt upgrade
Once the commands have been executed, the installation of Gnome 40 Ubuntu will be complete and a reboot of the computer will be required.
It is recommended to switch to the X.11 protocol (GNOME on Xorg). Wayland (GNOME) has a number of problems so far, including partially or completely broken applications. Also, older versions of Electron will not run with the new protocol, and you cannot drag and drop files from File-Roller into Nautilus Explorer.
GTK4 libraries are used here, which moved to the new NGL engine. So the developer managed to achieve a more efficient use of computer resources even when selecting program rendering.
But the main differences occurred in the interface of the shell. GNOME 3 already had desktops called by the Browse button, not connected to the Applications menu.
Now, after logging in, the user is greeted by a reimagined Overview. The desktops are arranged horizontally. The Dock has moved to the bottom.
Next we see Applications and Overview now represent a single entity. The GNOME 3 concept of deliberately doing away with the Expand and Collapse buttons is slowly justifying the change. Desktops are now spaces for a wide variety of tasks.
The Dock has been given a dividing line to separate favorite applications. But there are several desktops, and the Dock is one, so it's hard to know at first which desktop a particular application belongs to.
So one way to interact with desktops would be to drag and drop icons to the desktops we want.
Some applications have also been updated, but the changes are not significant. The settings items have been worked through, Explorer options are now placed in one tab instead of several. Weather has become one of the few applications for the new shell with adaptive layout.
Now the shell is working unstably. Note that both third-party applications and native applications updated to version 40 hang.
Gnome Tweak Tool is installed and allows you to enable windows buttons (Expand, Collapse) and customize the appearance. Yaru, Ubuntu's proprietary theme, is supported, as well as others on GTK3, but the layout "moves off" in some places, as there are no parameters for new interface elements.
Extensions are even worse. Less than 20% for GTK3 got the 40th version. For example, there is an option to return icons to the desktop, but the dock panel has not been updated yet. You can use Plank, but it hangs a lot and doesn't work with Wayland.
On a positive note, extensions for GNOME 40 have started to appear. For example, No overview at startup
disables startup in overview mode, and Gesture enhancements expand the list of gestures.
Ubuntu 21.04 with GNOME 40 shell with tweaks and extensions
Note that the Mutter window manager does not support scaling with X.11, it is only available with the Wayland protocol.
After reading the instructions, you now know how to perform a Gnome 40 installation in Ubuntu. The updated GNOME 40 offers to use the concept of multiple desktops. But if in version 3 it was "raw", now the idea looks complete: the Applications menu is now inextricably linked to the desktops, and in particular to the Overview menu.
But not all users will like this solution, as it is still more suitable for touch control. And users are understandable. For a dozen years now, users have been offered a new interface, but applications are not really designed to work with touch controls. A good example would be Windows 10: the Windows 8 interface hasn't gone anywhere, it's just been relegated to tablet mode.
Ubuntu developers will have to work on the current state of the shell to improve its usability. Even the latest release of Fedora 34 on GNOME 40 is not stable and needs improvements.