A look at Linux Mint 21

Linux Mint 21 "Vanessa" was released on July 31. There are no real headline-grabbing features that come with the new release, as the project generally seeks to make incremental changes, rather than larger, potentially disruptive ones. Changes in this release include a new Bluetooth manager that brings several improvements, driverless printing and scanning by default, a process monitor to inform the user about resource-intensive background tasks, new functionality for the Timeshift system backup tool, and several major under-the-hood improvements to the Cinnamon desktop environment.

Like previous releases, Linux Mint 21 is available in editions for the Cinnamon, MATE, and Xfce desktop environments. Cinnamon is based on GNOME 3, but with major changes to make it more like other desktop environments with a bottom panel and menu similar to that used in Windows 7 and earlier, rather than the heavily redesigned interface of GNOME 3 and later. Cinnamon was created by the Linux Mint developers due to criticisms of changes in GNOME 3 that were seen as unnecessary. MATE is a continuation of GNOME 2 that was originally forked by an Arch Linux user for the same reason, and Xfce is a lightweight desktop environment designed for computers that may not run other environments well. All of the editions in Linux Mint use X11; Wayland support is not currently on the development roadmap for Cinnamon. MATE and Xfce are working on Wayland support separately from the Mint project, and a future release of Linux Mint is likely to include that work in those editions.

For many users, especially those new to Linux, who have suitable systems (which includes most computers from the last several years except for some low-end netbooks), Cinnamon is probably the best choice because its primary focus is user-friendliness. MATE and Xfce are specifically designed to be lightweight, which sometimes comes at the expense of features and user-friendliness. If a change could be made to improve usability at the cost of system resources, Cinnamon would likely make the change, while MATE and Xfce may not. Cinnamon is also the most popular option, making it easier to find help with problems. For these reasons, the Cinnamon edition is the focus of this article and some of the changes mentioned only apply to Mint Cinnamon.

Mint 21 is based on Ubuntu 22.04 LTS, which was released in April. This will be the package base for all 21.x Mint releases as well, so upgrades to those future versions will be straightforward. As with what shipped in Ubuntu 22.04, Mint 21 is based on the 5.15 Linux kernel.

Desktop tools

Mint 21 replaces Blueberry, the Bluetooth manager used in previous versions, with Blueman, which has more features and provides more information than Blueberry. Blueman also has better headset compatibility and improved audio profile support. Additionally, while Blueberry is a wrapper around the GNOME-specific gnome-bluetooth, Blueman is specifically designed to be cross-desktop.

Several of the applications included in Linux Mint are part of the distribution's "XApps" project, which develops desktop-independent GTK software. These programs are especially useful for distributions like Mint that offer several desktop environments, because developing an application for each desktop environment for a given function would lead to significant duplication of effort.

Cinnamon has relatively few tools of its own, other than things like the settings program that cannot really be separated from the desktop environment; it relies on XApps for other tools. Mint uses XApps in the other editions when necessary to fill gaps in features provided by those desktops, although desktop-specific tools are generally used by default if they are available.

XApps are also designed to work on any distribution, not just Mint. They are available, along with Cinnamon, for many distributions, including Ubuntu, Fedora, Arch Linux, and Debian. I have used Cinnamon and XApps extensively on my Arch Linux laptop, and it works quite well; I have also used several XApps in GNOME on Arch, and they work just as well as they do in Cinnamon.

The Timeshift system backup tool, which was formerly an independent project, is now developed by Linux Mint as an XApp. It has a new feature to completely avoid filling disks with backups when it is used in rsync mode; it now skips making automated backups that would leave less than 1GB of free space on the target filesystem. Timeshift creates system snapshots using rsync on all filesystems except Btrfs, which supports snapshots directly. Mint uses ext4 by default, so most users will benefit from the rsync mode improvement.

Linux Mint 21 adds support for displaying thumbnails for several previously unsupported file types, thanks to a new XApps project called "xapp-thumbnailers". AppImages now show the application icon, EPUBs show the book's front cover, MP3s show the album cover, while WebP and most RAW images show a typical image thumbnail. WebP support was also added to Xviewer, the XApp image viewer.

The new version of Mint also includes a process monitor panel applet in the Cinnamon edition. Mint has several resource-intensive processes that can run automatically, such as system updates and Timeshift snapshots. If these run while the computer is in use, they can slow the computer down. The process monitor does not solve this problem, but it does notify the user that the tasks are running. This way, while the computer is still slower while these tasks are running, the user is not left to figure out why.

Starting with this release, Mint uses the Internet Printing Protocol (IPP) for driverless printing and scanning by default. IPP has been supported since Mint 20, but drivers were still used by default in that release. The majority of printers and scanners will now work out of the box without the need to install drivers. Traditional drivers are still supported, though, so users with devices that do not support IPP can still use them.

Cinnamon/Muffin

Several major internal changes were made to the Cinnamon desktop and Muffin, its window manager. Muffin is based on Mutter, GNOME's window manager, but the code bases have diverged significantly over time. Muffin forked from Mutter 3.2 eleven years ago, and both projects have made changes over time, making it increasingly difficult to merge Mutter updates into Muffin. With Cinnamon 5.4, the new version used in Mint 21, Muffin has been rebased on Mutter 3.36, and has fewer differences from the upstream code. This release also moves the handling of display settings from Cinnamon to Muffin.

Window decoration handling was also improved. GTK applications can have their header bars rendered in two different ways: by the client application (client-side decorations, or CSD) or by the window manager (server-side decorations, or SSD). Traditionally, server-side decorations have been used, but many applications are switching to client-side decorations. Advantages of CSD include improved use of screen space and applications can have buttons for functions other than window controls in their header bars. Of course, these windows' header bars will look different because of the extra information shown, but some desktops also theme them differently, leading to an inconsistent user interface.

To reduce this inconsistency, the Mint developers made CSD and SSD window decorations as similar as possible with the Mint-X and Mint-Y themes. However, prior to this release, the title bars were rendered differently; CSD windows' decorations were rendered with GTK, while Muffin used Metacity to render those of SSD windows. The use of different rendering engines prevented the themes from making the decorations identical, and because GTK's antialiasing and rendering of rounded corners are smoother than Metacity's, SSD windows' decorations look slightly more pixelated than those of CSD windows. Starting with Cinnamon 5.4, GTK is used for both CSD and SSD windows' decorations, making them look identical.

Upgrading

Because Mint 21 switches to a new package base, the upgrade from 20.3 to 21 is significantly more complicated than, for example, that between 20.2 and 20.3. Previous major version upgrades, such as upgrading from Mint 19.3 to 20, required a lengthy command-line process that could go wrong in several places. However, a new graphical tool called mintupgrade makes the procedure much simpler for this upgrade, although it is still more complicated than a minor version upgrade. The instructions do require the use of the terminal, but no knowledge of the Linux command line is needed.

Only Mint 20.3 can be upgraded directly to 21; other releases must be upgraded to one or more intermediate releases. The Mint user guide has more information on available upgrade paths. As with previous releases, users are not required to upgrade right away. Several older versions are still supported; 19.x releases are supported through April 2023, while 20.x releases are supported through April 2025. Linux Mint 21 is a long-term support (LTS) release that will be supported until April 2027.

Conclusion

While Mint 21 does not have many major, attention-grabbing changes, this release makes several relatively small but still significant improvements. Things like the replacement of Blueberry with Blueman, the addition of the process monitor, or the switch to driverless printing are relatively minor changes, but put together, they improve the user experience. The Linux Mint project tends to avoid large, needless changes, as shown by the original motives for developing Cinnamon; the project continues this philosophy by focusing on small improvements even in major-version updates.