KaOS Linux 2025.07: KDE Plasma 6.4.3 on Qt 6.9.1 (Qt6-only)

KaOS Linux 2025.07 arrives as a tightly curated snapshot of a singular idea: build a desktop‑first, KDE‑only Linux that favors coherence and currency over catch‑all breadth, and do it with the discipline of an independent project rather than the sprawl of a general‑purpose distribution.

What the 2025.07 snapshot delivers​

KaOS 2025.07 takes a predictable naming scheme—the month of the ISO refresh—and uses it to showcase the project’s current baseline. For July 2025, that baseline advances to KDE Plasma 6.4.3 on top of the Linux 6.15 kernel, with the full KDE software stack aligned around Qt 6.9.1. KDE Gear 25.04.3 and KDE Frameworks 6.16 complete the trio, ensuring the desktop, its underpinning libraries, and its application set move in lockstep.
This cycle also marks ongoing consolidation around a Qt 6‑only world. KaOS had been staging toward a Qt 5‑free repository for some time; with 2025.07, that transition is no longer a goal but day‑to‑day reality. More Qt 6 applications are present out of the box, including a revived Amarok music player port and plasma‑keyboard for on‑screen input. The distribution further flags a strategic change at the login screen: a Plasma‑native login manager is available in the repositories and is expected to replace SDDM after additional bake time.
Under the hood, the snapshot gathers a dense roster of current toolchain and middleware updates: Mesa 25.1.6 for graphics, PipeWire 1.4.6 for audio and video routing, CMake 4.0 for builds, Glib2 2.84.3 and GStreamer 1.26.4 for core GNOME/GTK interoperability and multimedia pipelines, and systemd 254.27 for init and service management. Security and storage components advance too, with OpenSSL 3.5.1, Protobuf 31.0, Poppler 25.07.0, SQLite 3.50.3, IWD 3.9, cURL 8.15.0, OpenZFS 2.3.2, and tzdata 2025b in the mix. The base tooling includes Perl 5.40.2, GNU Bash 5.3, and Shadow 4.18.0.

The KaOS philosophy, revisited​

KaOS remains a study in intentional scope. Unlike distributions that ship multiple desktops and maintain compatibility layers for divergent stacks, KaOS narrows its surface area to a single experience: KDE Plasma and the Qt toolkit. That choice has consequences—fewer redundant settings panels, fewer theme mismatches, and fewer cross‑toolkit edge cases—but it also means a smaller official repository and a sharper set of expectations about what ships and why.
Independence is the other pillar. KaOS uses pacman, the package manager popularized by Arch Linux, but the repositories are not Arch’s. Packages are built and maintained for KaOS, with versioning and patches aligned to the project’s goals. There is no AUR; community contributions flow through KaOS‑specific channels, and the project curates what lands in the main repos to protect the coherence of the stack.
This design ethos tends to attract those who value stable, consistent Plasma behavior and who prefer a single, modern graphics/audio stack rather than multiple legacy paths. It also suits systems where keeping a focused set of applications up‑to‑date is more important than accessing tens of thousands of optional packages.

KDE Plasma 6.4.3 on Qt 6.9.1: a coordinated desktop​

Plasma 6 consolidated the long‑running Wayland transition, refined energy and window management, and recast default settings around sensible modern hardware. The 6.4 series, and in particular 6.4.3, continues that cadence with stability fixes and polish passes that reduce update‑to‑update friction.

• Wayland by default: The assumption is now contemporary GPUs and input stacks. Compositing, fractional scaling, touch input, and high‑DPI behavior benefit from ongoing tuning, and Plasma 6.4.3 integrates those improvements with fewer regressions.
• System Settings clarity: The march toward simpler panels continues, with feature placement that better reflects real‑world workflows rather than historical layout.
• Discover refinements: The software center within Plasma gains incremental improvements in update visibility, permissions prompts, and error messaging, which matters more on a distro whose repositories are tightly curated.
• KWin stability: The window manager’s latency, tearing mitigation, and per‑display behavior see additional bug fixes, particularly under hybrid GPU and multi‑monitor setups.

Qt 6.9.1, the foundation for both Plasma and the majority of KaOS applications, is not merely a version bump. The 6.9 line brings continued performance work in rendering and input handling, broader support for modern C++ standards across modules, and refinements that help large, complex applications maintain responsiveness under load. When the entire distribution standardizes on the same toolkit, the aggregate gains in startup times, theme fidelity, and font rendering consistency compound across the experience.

A Qt 5‑free distribution: what that really means​

Dropping Qt 5 is not a superficial housekeeping decision; it removes an entire parallel universe of libraries, plugins, and theme assets. This brings clear benefits:

• Smaller surface area for security and compatibility issues, since only one toolkit branch is maintained.
• Unified theming and widget behavior, eliminating mismatches between Qt 5 and Qt 6 style engines and icon handling.
• Better memory locality and fewer duplicate resident libraries.

There are trade‑offs, too:

• Legacy applications not yet ported to Qt 6 will not be present in the repos unless they have been forward‑ported or replaced.
• Some niche utilities may be missing or in transition, pushing users toward alternatives or sandboxed packaging if available.

KaOS uses this constraint intentionally. Rather than carrying both toolkits for another cycle or two, the project has placed a clear line in the sand that accelerates the KDE ecosystem’s migration within its own borders. With 2025.07, new applications such as plasma‑keyboard and Amarok showcase the payoff from focusing effort on Qt 6 ports and Plasma‑native solutions.

plasma‑login‑manager: a Plasma‑native session front door​

SDDM has long served as the display manager in KDE‑centric distributions, providing the greeter, session selection, and authentication hand‑off into the desktop. KaOS 2025.07 introduces plasma‑login‑manager in the repositories as a next step toward a tighter integration model.
The concept is familiar: a login greeter written with the same technologies as the desktop it launches, with a compositor and input stack that match the session defaults. In practice, a Plasma‑native login manager can deliver:

• More consistent theming, since the greeter and desktop use shared style definitions and assets.
• Better Wayland alignment, with compositor behavior and input devices handled by the same codebase and assumptions.
• Fewer dependencies, because a Plasma‑tailored greeter avoids pulling in non‑Plasma components solely to bridge gaps.

In this snapshot, plasma‑login‑manager is installable but not yet default. Expect it to replace SDDM once migration edge cases—complex keyboard layouts, biometric modules, or encrypted root setups—have been fully vetted.

Linux 6.15: kernel‑level changes that matter on the desktop​

KaOS 2025.07 lands on Linux 6.15, which brings incremental but meaningful progress across graphics, storage, and power management. The kernel’s fast‑moving DRM subsystem continues to track new GPUs and APU generations, with updates across AMD’s amdgpu, Intel’s i915/xe, and NVIDIA’s open kernel modules compatibility surfaces. These land as a mix of new device IDs, stability fixes, and performance enhancements in display pipelines.
Storage subsystems see continuing improvements to Btrfs and ZFS interoperability (ZFS via the OpenZFS project), while ext4 and XFS carry on their steady reliability and tooling advances. The input stack folds fixes for modern touchpads, wireless dongles, and Bluetooth LE devices—a typical mid‑cycle crop that translates directly into plug‑and‑play success on newer laptops.
Power management, particularly on recent Intel and AMD mobile parts, benefits from scheduler and cpufreq refinements that help idle states and boost behavior play nicely with real‑world workloads. Audio quirks for UCM profiles and USB interfaces also see the usual sprinkling of fixes, which matter directly to PipeWire‑based desktops that rely on accurate device graph detection.

A focused graphics, audio, and media stack​

KaOS leverages three major subsystems to deliver its desktop experience: Mesa for graphics, PipeWire for audio and video routing, and GStreamer for multimedia pipelines. The 2025.07 snapshot moves all three forward.

• Mesa 25.1.6: Mesa’s cadence is relentless, and 25.1.x is a well‑traveled point series with driver stability and performance tweaks for AMD and Intel GPUs. Vulkan drivers, shader compilers, and Gallium‑based OpenGL implementations benefit from multiple rounds of regressions fixes and feature expansions that help both gaming and desktop compositing.
• PipeWire 1.4.6: The 1.4 line consolidates multi‑client stability, Bluetooth codec handling, and latency behavior under load. Desktop audio on PipeWire now routinely handles screen capture, low‑latency monitoring, and pro‑audio scenarios without devolving into JACK/PulseAudio gymnastics.
• GStreamer 1.26.4: Codec and demuxer updates reduce surprises when handling modern media containers, while hardware‑accelerated decode paths continue to broaden across iGPU generations.

The practical upshot: fewer synchronization hiccups in video calls, fewer broken streams when juggling USB mics and HDMI audio, and more consistent performance across compositing, media playback, and gaming.

The core toolchain and libraries: incremental but essential​

A desktop distribution is more than its kernel and DE. KaOS layers a current toolchain and a set of widely used libraries that enable everything from system initialization to net new application builds.

• systemd 254.27: Service management and boot sequencing remain predictable with modern sd‑boot and systemd‑journald tooling. KaOS keeps to a deliberate pace here to guard against regressions in core boot paths.
• OpenSSL 3.5.1: Cryptography libraries stay fresh, which helps browsers, package delivery, and secure messaging stacks abide by current cipher policy.
• Protobuf 31.0 and SQLite 3.50.3: Serialization and embedded database engines are ubiquitous in modern apps; their updates reduce edge bugs and improve performance on large datasets.
• Glib2 2.84.3: Even within a Qt‑centric desktop, Glib’s event loop and utility APIs are common dependencies. Keeping glib aligned with recent releases avoids classpath and symbol clashes when cross‑toolkit software is present.
• IWD 3.9 and cURL 8.15.0: Wireless and HTTP/HTTPS primitives get the kinds of updates that move needle on WPA3 stability, TLS handshake performance, and certificate validation.
• OpenZFS 2.3.2 and tzdata 2025b: Filesystem snapshots and timezone correctness are less glamorous than desktops and compositors but loom large when protecting data and keeping schedules straight.
• Perl 5.40.2, GNU Bash 5.3, and Shadow 4.18.0: The unheralded trio behind many system scripts and user management routines benefits from bug fixes and security hardening.

CMake 4.0 deserves a special note. Build systems are rarely headline news, but the 4.0 milestone signals evolved defaults, modern C++ standard assumptions, and better integration with package find modules. For a distribution that encourages native Qt/KDE development, this translates into easier builds and fewer bespoke patches.

Installation and the update path​

KaOS continues to target modern 64‑bit UEFI systems and ships a polished live environment with a graphical installer. The project has long worked with Calamares to deliver predictable partitioning, encryption, and locale workflows, and the 2025.07 ISO preserves that predictability with the updated software baseline preloaded.
As with prior snapshots, the live ISO functions as both an installer and a recovery/update launchpad. For existing systems, the standard rolling update model applies: synchronize the package databases, refresh the keyrings, and perform a full system upgrade. The project’s notes consistently recommend a clean snapshot install only when repaving a system or recovering from a configuration state that no longer aligns with the repository’s assumptions—an edge case rather than a routine requirement.
The separation of the snapshot cadence (ISOs) from the rolling stream (repositories) allows KaOS to present a coherent, testable starting point for new installs while keeping daily drivers on the fast‑moving Plasma and kernel tracks.

Software availability and curation strategy​

KaOS’s repository strategy is deliberate. It carries the KDE/Qt stack in depth but chooses coverage over count for the rest. The result is a set of core system and developer packages that feel surprisingly complete for day‑to‑day work—browsers, office tools that respect Qt integration, terminals, editors, and utilities—without the redundancy found in larger distros.

• Reducing overlap: Multiple GTK apps that duplicate KDE tools are generally not included unless there’s a clear functional gap.
• Emphasizing quality: Packages are built against the same toolchain and tested within the same Plasma environment, which reduces the “works on my desktop but not in the live session” problem.
• Managing transitions: The Qt 6 pivot evidences a willingness to break with compatibility when the net benefit is clear, but the project typically provides migration windows and alternative paths where feasible.

Access to containerized or sandboxed packaging can fill gaps when necessary. Flatpak support, for example, runs acceptably well alongside a Qt‑native desktop, though KaOS’s preference remains native packaging for performance, integration, and security review reasons. The project’s stance is to avoid offloading core functionality to universal packaging unless the gain clearly outweighs the loss of control.

Drivers, firmware, and hardware support​

Kernel and Mesa updates carry most of the load for new hardware, but KaOS also pays attention to UEFI quirks, NVMe controller peculiarities, and wireless firmware rows that crop up across laptop generations. IWD and NetworkManager cooperation is a specific focus, as is ensuring that Bluetooth LE audio and HID devices show up with the right profiles and permissions.
For storage, OpenZFS availability is a competence boost for power users who rely on snapshots and checksumming. Ext4 remains the default for those who prioritize simplicity, while Btrfs continues to improve with its subvolume and transparent compression features. KaOS does not chase every filesystem permutation; it chooses sane defaults and maintains a short list of alternatives that are well tested in the live environment.
On the graphics side, the promise of Mesa 25.1.6 and Linux 6.15 is twofold: better out‑of‑the‑box support for GPUs released over the last year, and less babysitting for hybrid graphics laptops. Plasma’s Wayland session benefits as GPU driver teams keep closing gaps on color management, variable refresh rate behavior, and multi‑monitor layout persistence.

Security posture and update discipline​

KaOS’s security model starts with a smaller attack surface. Fewer packaging formats and fewer parallel toolkits reduce the number of paths into the system. The distribution tracks security advisories for its curated set of packages and tends to move quickly on OpenSSL, cURL, and systemd‑related updates that have broad blast radii.
Shadow 4.18.0, OpenSSL 3.5.1, and a current tzdata set are representative of the project’s keep‑current bias for security and correctness components. Kernel minor updates flow in regularly, bringing both security fixes and the incidental stability improvements that accompany them. The maintainers’ preference is to ship fixes in situ rather than backport across large version gaps, which suits the rolling model and avoids the complexities of maintaining long‑term divergence.
The expected migration from SDDM to plasma‑login‑manager will warrant careful attention to PAM stacks, theming, and accessibility features at the login stage. The KaOS approach—ship the new greeter in repos first, allow real‑world testing, then flip the default—reflects a security‑conscious stance that privileges staged rollout over big‑bang switches.

Developer experience on KaOS​

A distribution that lives at the intersection of KDE and Qt naturally doubles as a fertile ground for building Qt 6 applications. With Qt 6.9.1, CMake 4.0, and a current Clang/GCC toolchain, KaOS positions itself as an efficient development workstation for Plasma‑aligned projects.

• Predictable headers and libs: The repos keep -dev/-devel packages aligned with the runtime versions, preventing the mismatches that plague mixed‑toolkit environments.
• Modern C++ workflows: CMake 4.0 and contemporary compilers enable C++20/23 features by default, which in turn allows projects to simplify code paths.
• Native theming and HIG alignment: Testing applications within a fully Qt 6 Plasma desktop reveals integration flaws early, from icon naming to palette usage and high‑DPI scaling behaviors.

For cross‑toolkit work, KaOS maintains the minimum set of GTK and GNOME libraries necessary for interoperability, but it resists the temptation to become a generic dev host for every ecosystem. That constraint is, again, deliberate; if the target is Plasma/Qt, KaOS provides a clearer runway than broader‑scope distros.

Desktop polish and daily usability​

Much of KaOS’s value proposition is about what doesn’t happen: no cascading theme changes when a legacy Qt 5 app launches; no abrupt jumps between cursor themes across applications; no inconsistent font rendering because of mixed toolkit backends. The entire stack—from SDDM today to plasma‑login‑manager tomorrow, from KWin to Discover—shares the same design language and the same primary toolkit.
Daily workflows benefit from:

• Reliable suspend/resume on laptops, helped by kernel and firmware updates and Plasma’s maturing power profiles.
• Sound device sanity, as PipeWire mediation and updated ALSA UCM profiles remove many common edge cases.
• Fractional scaling and multi‑monitor competency under Wayland, an area that has strengthened steadily across Plasma 6 releases.

The distribution’s restraint extends to defaults. Only a small set of preinstalled applications are present, most of them KDE projects. Optional extras—office suites, creative tools, IDEs—are a few clicks away, but the live image avoids loading the ISO with a maximalist selection.

Comparisons and positioning among KDE‑centric distros​

KaOS occupies a unique space alongside projects like KDE neon, Fedora KDE Spin/Kinoite, Arch (with Plasma), and openSUSE Tumbleweed/Krypton:

• Against KDE neon: Neon prioritizes the latest Plasma on top of an Ubuntu LTS base, giving stability in the base system and cutting edge for the desktop. KaOS pushes currency across the stack—kernel, Mesa, tools, and desktop—while keeping the scope narrow and independent of Debian/Ubuntu packaging timelines.
• Against Fedora KDE Spin/Kinoite: Fedora’s KDE offerings inherit Fedora’s dynamism and enormous repo breadth. KaOS trades that breadth for a coherent Qt‑only experience with a curated set of packages that move mostly in sync.
• Against Arch with Plasma: Arch offers maximal choice via AUR and rolling repos. KaOS borrows the pacman ergonomics but replaces the substrate with its own repositories and a policy layer that enforces KDE/Qt focus.
• Against openSUSE Tumbleweed/Krypton: Tumbleweed’s snapshot model and vast build service enable myriad desktop permutations. KaOS instead hews to a single desktop paradigm, minimizing the variability that multiple desktops introduce.

In practice, KaOS’s value stands out when the goal is a current Plasma desktop on a distribution that rarely asks the user to mediate between divergent stacks or packaging philosophies.

Games, graphics APIs, and performance considerations​

Gaming on KaOS benefits from the same advances that lift all modern Linux gaming: current kernels with robust scheduler behavior, Mesa’s fast‑moving Vulkan drivers, and Proton/Wine improvements that bubble up through Steam and related layers. The distribution’s focus on contemporary GPUs and Wayland compositing can be an asset for consistent frame pacing and HDR pipeline work, provided the hardware and game stack align.

• Vulkan drivers: Mesa 25.1.6 continues to expand and optimize Vulkan across AMD and Intel paths, with shader cache and pipeline compiler improvements that reduce stutter.
• OpenGL: While gaming has moved toward Vulkan, OpenGL remains central for emulators and many native titles; the Gallium stack sees ongoing fixes that matter for these workloads.
• Latency and sync: PipeWire and KWin tuning reduces input‑to‑photon latency in desktop contexts, though specialized gaming setups may choose additional compositor settings or switch to a no‑compositing mode when appropriate.

KaOS does not attempt to incorporate every gaming tool by default; it provides the current graphics and audio bedrock, and expects specialized layers to be added selectively. This keeps the base image light and the update cadence focused.

Internationalization, input, and accessibility​

The adoption of plasma‑keyboard and the Qt 6 input method framework narrows the gaps in virtual keyboard and complex script support under Wayland. Locale handling in Calamares remains straightforward, and the KDE language packs inherit Plasma’s improved panel and applet translations.
Accessibility tooling benefits from Plasma’s evolving screen reader hooks and high‑contrast themes, and the migration toward a Plasma‑native login manager should ultimately yield better continuity from greeter to desktop for those workflows. As with many desktop environments, the most sensitive accessibility features improve steadily rather than dramatically; KaOS’s job is to track those upstream advances promptly and test them in a coherent environment.

The case for KaOS 2025.07 on modern hardware​

New laptop owners and desktop builders looking for a current, KDE‑forward distribution will find KaOS 2025.07 aligned with that brief. The live ISO surfaces the project’s practical strengths: quick boot, a clean Plasma session, predictable device detection, and an installer that handles common partitioning schemes and encryption without fuss.
What stands out after installation is the absence of drift. Because the repos only carry one primary desktop stack, update cycles rarely produce the kind of split‑brain scenarios that occur when multiple toolkits and desktops evolve at different rates. When breakage does occur, it is usually limited to a small set of packages and addressed inside the project’s own packaging pipeline, rather than requiring coordination across disparate repositories.
The flip side, again, is selectivity. Niche or legacy software built on Qt 5 or older GNOME/GTK stacks might not be readily available. Workflows that depend on those tools will need to adapt or rely on sandboxed packaging where appropriate. KaOS’s maintainers have signaled that the new Plasma login manager will take over from SDDM once remaining edge cases are ironed out; until then, both are available, with SDDM as the default.

Bottom line​

KaOS Linux 2025.07 is a confident snapshot of a mature idea executed with precision. Plasma 6.4.3 on Qt 6.9.1 feels coherent because everything around it points the same way, from the kernel and Mesa to PipeWire and the curated application set. The decision to live without Qt 5 clears technical debt and smooths daily desktop use, while the introduction of a Plasma‑native login manager signals the project’s willingness to evolve longstanding components when the payoff is clear.
By standing apart from larger, general‑purpose ecosystems and embracing a rolling, KDE‑only model, KaOS accepts trade‑offs in breadth to gain consistency and speed. For systems built around modern hardware and workflows that thrive in a Qt‑first world, the 2025.07 release provides a clean, current baseline that feels faster not because of marketing claims, but because the pieces fit.

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Source: 9to5Linux Independent Distro KaOS Linux 2025.07 Is Out with KDE Plasma 6.4 and Linux 6.15 - 9to5Linux