KaOS is pleased to announce the availability of the May release of a new stable ISO.

Qt5 has been end of life for quite a few years now, but the move of all applications to Qt6 has been slow-going, but with this ISO it is finally at a point that a default install will be Qt5 free from now on. There is no Qt5 of KDE Frameworks based on Qt5 included. Qt5 has not yet been removed from the repositories, so it is still possible to add Qt5 based applications after the installation (but complete Qt5 removal is planned for the near future).

For the Plasma desktop, the latest Plasma (6.3.5), KDE Gear (25.04.1), and Frameworks (6.14.0) are included. All built on Qt 6.9.0. Among the many changes included in KDE Gear 25.04 are:

• Dolphin now comes with initial support for right-to-left written languages, such as Arabic or Hebrew.
• KRDC allows you to scale down the remote machine’s desktop to fit inside KRDC’s window, adds support for the domain field in the authentication process, and now works with the new version of the FreeRDP protocol.
• Okular, KDE’s document viewer, ramps up its support for digital signing with support for PGP/GPG based signatures and Falkon can now also block websockets.

_{Clone Panels, duplicate your setup with one click} Latest applications that are now ready to use Qt6 and Frameworks 6 include Frescobaldi, Krita, Kamoso and Calligraplan.

Updates to the base of the system were numerous and included a new Toolchain based on Glibc 2.4.1, Binutils 2.44 & GCC 14.2.1, SQlite 3.49.1, Pacman 7.0.0, kmod 34.2, IWD 3.4, Poppler 25.05.0, Gstreamer 1.26.1, Pipewire 1.4.3, kernel moved to Linux 6.14.8, Systemd 254.24, ZFS 2.3.2, Tzdata 2025b, OpenSSL 3.5.0, Proj 9.6.0, Protobuf 31.0 and Mesa 25.1.1.

Among the new packages included is Nextcloud-client, an opensource sync client for Nextcloud. _{Frescobaldi Qt6 based}

Support has been added for the new filesystem bcachefs, it is still in experimental stage, but is included in the kernel build, and the needed bcachefs-tools are available in the repositories. Calamares can use bcachefs when used in manual mode, though no specific settings for this filesystem have been implemented yet. _{Bcachefs used for an installation}

A new Phonon sound backend is in use. So far VLC was used, but there is no Qt6 porting for VLC yet. Using phonon-mpv as default now gives a fully Qt6-ready backend.

SDDM 0.20.0 added the option to run this display manager in Wayland mode, so KaOS is one step closer to being ready to move away from X11. The shell used to run in Wayland mode is kwin_wayland (upstream default is using Weston). _{Krita Qt6 based}

The automated partitioning option in the installer (Calamares) offers the use of all popular filesystems, so no need to use manual partitioning to be able to choose XFS, EXT4, BTRFS, or ZFS.

Big thanks goes to YourHostingSolutions for not only providing a mirror, but also providing a server for KaOS. With the discontinuation of Fosshost, a new server was sorely needed.

Getting good logs has always been a bit of a challenge since you have to know what journalctl commands to use. That is now a thing of the past, Kjournald gives the option to view the logs from a nice GUI, with all kinds of filter options in the left-hand pane (it is part of the default install)

Common Notes

The Linux kernel has all the needed ucode build-in for a fully automated Early Microcode update.

KaOS uses the Systemd-provided Systemd-boot for UEFI installs.

KaOS’ creation Croeso (Welsh for welcome) for helping with configuring a new installation is included. It will run on the newly installed system and offers to adjust some 15 commonly used settings, includes a custom Wallpaper selector, distribution info, and the option to select packages to install from six different groups. It is written in QML and fits well with the Welcome application used in the Live system. The latter includes an Installation Guide.

This ISO uses the CRC and finobt enabled XFS filesystem as default. CRCs enable enhanced error detection due to hardware issues, whilst the format changes also improves crash recovery algorithms and the ability of various tools to validate and repair metadata corruptions when they are found. The free inode btree does not index used inodes, allowing faster, more consistent inode allocation performance as filesystems age. _{The installer Calamares} The artwork includes a custom icon theme for light themes. Midna creates a complete, unified look from boot-up all the way through logout.

There is an option to verify the authenticity of downloaded KaOS ISO files through GPG signature verification, see the Download page for further details and instructions.

Known issues:

• Installing on RAID is currently not possible

To create reliable installation media, please follow the instructions from the Download page. KaOS ISO’s do not support Unetbootin or Rufus, and DVDs need a burn speed no higher than 4x.