I've used every immutable Linux distro, and this is the one I'd install today – here's why

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ZDNET’s key takeaways

• Ultramarine has a new default desktop, and it’s still outstanding.
• This immutable distribution is rock-solid, secure, and Linux to its core.
• You can download and install Ultramarine for free.

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Ultramarine Linux is a spin of the Fedora desktop distribution that not only “just works” out of the box, but always works… period.

This open-source distribution achieves that feat by being immutable (which means the core of the OS is mounted in read-only mode, so it cannot be changed). That immutability sets it apart from its base, providing a significantly higher level of security.

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But Ultramarine isn’t just about offering rock-solid security.

Ultramarine is also an amazing desktop distribution for those who want to be creative, productive, or entertained.

With the release of Ultramarine 43, several changes will be important for users.

RPM is back, baby

Prior to version 43, Ultramarine pushed Flatpak as the default package manager. With this new release, the developers listened to the community and have brought back the option to use RPMs instead. 

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This will satisfy a lot of users who see Flatpaks as a waste of system resources (CPU and RAM in particular). 

Readymade

Ultramarine has chosen to use Readymade, an OS installer that greatly simplifies the Linux installation. Readymade is easily on par with the newest Ubuntu installation to make it one of the easiest I’ve ever used. 

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Readymade is a GUI front-end for systemd-repart, a tool that automatically manages disk partitions to allow for the creation and resizing of disk partitions based on predefined configuration files. 

Readymade makes it possible for anyone to install Linux. It really is that simple. With just a few quick clicks, you’re done.

The new default desktop

Goodbye “Flagship” brand.

For years, Ultramarine Linux offered Budgie as the flagship (default) desktop environment. With the release of version 43, all that changes. Now, the flagship version uses KDE Plasma. This move doesn’t surprise me in the least, given how KDE Plasma has become one of the finest Linux desktop environments available.

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Over the years, I’ve watched KDE Plasma not only improve exponentially but also become increasingly popular. Once upon a time, finding a distribution that offered KDE Plasma as the default desktop could be challenging. You can now find plenty of distros that default to Plasma, and Ultramarine Linux is now one of them.

According to the official Ultramarine 43 release page, “KDE Plasma’s 6.0 release made Plasma into a highly polished, modern experience, and it’s only gotten better since. KDE and the Fedora KDE SIG put an insane amount of effort into Plasma, from its 5-Minute-Bugs initiative to dropping X11 support before GNOME.”

Ultramarine has dropped the “flagship” title and is simply recommending the Plasma edition as the best option for “newcomers and indecisive people.”

Yes, you can still download a version with Budgie, as well as Xfce and GNOME. Simply select the desired option from the Ultramarine download page and follow the installation instructions.

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Given my newfound love of KDE Plasma, I opted to download that version to see what it was all about. Like the previous Ultramarine releases, 43 is just plain wonderful.

You still get all the software you need out of the box  — LibreOffice, Firefox, KDE Connect, Elisa (a new music player), Haruna (a multi-media player), Kamoso (webcam software), and much more. If you don’t find what you need, launch KDE Discover and install the required software with a single click.

It should come as no surprise that the default theme is dark (why, oh, why?). Thankfully, KDE Plasma makes it very easy to switch to a lighter theme or download third-party themes from System Settings > Colors & Themes > Global Theme.

All other desktop editions have also been updated, so you can get:

• Plasma 6.5
• Budgie 10.10
• Xfce 4.20
• GNOME 49

Performance

As I’ve experienced with Ultramarine previously, performance is top-notch. Actually, I’d go so far as to say it feels a bit zippier compared to previous releases. This is probably due to KDE Plasma. Apps open quickly, installations are fast, and upgrades are painless.

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I ran through my usual process of installing Ollama (localized AI) to see how well it performed. When I was ready to run a query, I did my usual:

What is Linux?

Ollama immediately spat out the response, which was impressive, given the limited resources I assigned to the virtual machine. However, this is Linux, so I expect nothing less than outstanding performance.

My recommendation

After using Ultramarine over the weekend, I came to the conclusion that migrating to KDE Plasma as the default was the right move to make. Yes, I love the Budgie Desktop, but KDE Plasma offers a much more familiar and reliable desktop for those who might opt for an immutable Linux distribution, such as Ultramarine. 

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If you’re on the fence about this distribution, I highly recommend giving it a try. It performs brilliantly, looks great, and offers the usual flexibility, security, and reliability that comes with the Linux OS.

Download an ISO of Ultramarine Linux today and either burn it on a USB drive or spin it up as a virtual machine with VirtualBox. Either way, I’m confident you’ll be impressed.