A NixOS desktop you can install and look after through a graphical interface.
sekka.computer introduces Sekka and keeps its latest ISOs. aizome.computer shows Aizome, Sekka's own desktop, and every one of its apps.
Sekka is NixOS with a desktop of its own: Aizome, written in Rust from the compositor up. Genkan, a graphical installer, sets it up; Yukimi, an app for software and system updates, keeps it current; and Tatami, a keyboard-driven tiling desktop, is there for people who would rather tile. Sekka uses Determinate Nix and lets you choose Aizome, Tatami, Plasma, GNOME, vanilla Hyprland, or Xfce—or install several and switch at login. Sekka and Aizome are in daily use on many machines, their developer's and their users'.
- Installation takes a whole disk. Genkan erases the disk you choose. There is no dual boot, manual partitioning, or option to keep an existing operating system, so keep your files elsewhere.
- Installing needs an internet connection. RAID, LVM and offline installation aren't offered.
- For x86_64 PCs, with Secure Boot off. There is no ARM image.
- Generations aren't backups. They return you to an earlier system, not to earlier documents. Btrfs is available without automatic filesystem snapshots.
Googlebook images are temporarily unavailable. The PC ISO does not support Googlebook firmware, and experimental Googlebook support has not yet been validated on hardware. See the developer notes for its current status.
Images below link to their original, full-resolution PNGs, captured with a scale of 2, at twice the density of the layout. Desktops are shown whole, and each application on its own, cropped to its window. Nothing is upscaled. They come from test VMs built from Sekka's own modules; see screenshot provenance.
Aizome 藍染 is the desktop Sekka is made for, selected by default in the installer with Tatami beside it. It is written from the compositor up in Rust, on its own native toolkit, Sukumo 蒅, and takes its ideas from Haiku, NeXTSTEP and IRIX:
- Every window wears a tab only as wide as its title. A new window of the app you're using opens as another tab on its window (Settings can turn this off). Drop one tab among another window's and the windows stack into a group, from any apps, the tab going where you dropped it; drag a group's tab back in elsewhere to reorder it (Alt-drag for the one showing), and slide a tab along the top edge with Shift.
- One menu bar shows the focused app's menus. Super + right-click anywhere opens the whole menu at the pointer, and any menu tears off into a palette.
- Super + Space opens the command palette: every command in the focused app's menus, with its shortcut taught back to you, and windows, files, apps, settings and arithmetic.
- The Toolchest launches apps and places, the Deskbar lists each app with its windows and files its notifications beneath it, and Desks keep work apart (Super + Ctrl + ↑ shows them all).
- Drag the strip along the Deskbar's top to stand it at the left or right, and its inner edge to make it wider, slimmer or icons only. Right-click the strip for its named sizes.
- Super is the command key in every app (Super + C, Super + V), and the terminal opens in fish.
- Each keyboard keeps its own modifier keys, Caps Lock and Compose key. When you plug in or pair a keyboard, Aizome offers to set it up: press the key beside its space bar and Settings suggests where Super should go, so it sits under your thumb on a Mac keyboard and a PC keyboard alike. A laptop's own keyboard is set up from Settings → Keyboard. Layouts and shortcuts are the same on every keyboard. Keyboards don't yet keep their own keys under an input method (IBus or Fcitx 5): while one handles your typing, every keyboard types with the keys of the one in use when it began.
- Browsers, Electron apps, Zed and Flatpaks open and save files in Aizome's own chooser: Files' sidebar and path bar over the app's window, with its filters and options. Qt apps, and GTK 4 apps that don't ask the desktop portal, still show their own dialogs.
It comes with its own apps: Settei (Settings), Yukimi, Hako (Files), Sumi (Text Editor), Fusen (Notes), Koyomi (Calendar), Tokei (Clock), Soroban (Calculator), Tenki (Weather), Tansu (Disks), Kura (Disk Usage), Myaku (Activity), Nisshi (Logs), Shashin (Images), Shiori (Documents, a PDF reader), Utsushi (Media Player) and Koe (Dictation). Nisshi reads the system's journal and /var/log, suggests filters from what wrote each message, and asks for an administrator's password only to read what you can't. See its README for what is done and what isn't, and aizome.computer for every app in detail.
Super + Return opens Hotaru 蛍, Aizome's own terminal, and programs that need a terminal open in it too. Hotaru draws with the processor. It doesn't implement synchronized output (DEC mode 2026), in-band resize (2048), the Kitty graphics protocol, DEC modes 1039 and 1045, or DECSASD; foot is still installed for programs that want them. To use foot instead, choose it in Settei, under General → Default Apps → Terminal. Upgrading from a Sekka without Hotaru switches foot to Hotaru once; if you had chosen another terminal, it stays.
Aizome in a NixOS test VM, rendering in software.
Choose your disk, account, desktop, applications, location, and keyboard. Review everything before confirming erasure. Genkan prepares the system while you review it, then copies the prepared system to disk. Genkan opens when the live session starts, and it is an Aizome app: it shares Aizome's look and menu bar, and follows its Night and Day themes.
Genkan's window in preview mode, with sample data, in Aizome.
You can enable LUKS2 disk encryption on the disk page and choose a separate passphrase to unlock the system at startup. The system, personal files and optional swap are encrypted; boot files remain unencrypted. It works with ext4, Btrfs or XFS, using UEFI or legacy BIOS. Encryption is off by default. Remember the disk passphrase: changing your login password does not change it, and Genkan cannot recover it. TRIM is enabled through encryption to let SSDs reclaim space; this reveals which disk blocks are unused.
Installed systems start behind Sekka's boot splash: the crest on the night ground, with a thin rail that fills as the computer starts, and "Restarting" or "Shutting down" when it stops. Press Esc at any time to see the boot messages, and Esc again to go back; after 15 seconds the splash reminds you. On an encrypted system you type the disk passphrase into the splash, which points out Caps Lock; one passphrase opens both the system and its swap. A system installed before the splash came keeps starting without it, and updating doesn't change that: turn it on in Aizome's Settei → General → Startup, or with sekka-update --choose calamares.bootSplash.enable=true, and it shows from the next start.
The optional GitHub step can import your public SSH keys and set your Git identity. You can also carry your live session's Wi-Fi connections into the installed system.
The keyboard step asks you to press the key just left of your space bar. Aizome's command key is ❖ (Super), as ⌘ is on a Mac, and it belongs under your thumb: if that key is Alt, as on most PC keyboards, Genkan strongly recommends swapping left Alt and Super, and you can keep your keys as they are instead. Right Alt (AltGr) stays available for accents and symbols. If it's ❖ already, as on a Mac, nothing needs changing. Genkan swaps nothing else: with another key there, your keys stay as they are, and Settings can rearrange them after installing. The layout and the swap apply to every keyboard of the installed system, from the login screen and the console to Aizome and Tatami; Aizome still offers to set up a keyboard you plug in later with keys of its own. Genkan hears the key through Aizome, so started anywhere else, it lets you choose the swap without pressing it.
Genkan's keyboard step in preview mode, in a test VM, having heard the Alt key beside the space bar of QEMU's keyboard.
With Aizome, your terminals (Hotaru, foot, and the others) open in the fish shell set up as Omarchy sets it up: Omarchy's Starship prompt, vi keys, ls as eza, a cd that falls back to zoxide, and fzf searches of your history (Ctrl + R), files (Ctrl + Alt + F), and Git log and status (Ctrl + Alt + L, Ctrl + Alt + S). Bash stays your login shell and runs scripts. Functions in your own ~/.config/fish and a ~/.config/starship.toml replace Omarchy's. Some of Omarchy's shortcuts call tools fish doesn't bring, such as tmux, ImageMagick, or ffmpeg, and iso2sd and try depend on Omarchy itself, so they don't work. Without Aizome, terminals open in bash, as in Omarchy; the Terminal shell choice on Yukimi's Desktops page turns fish on there, or off with Aizome. Hotaru also accepts a shell override in its configuration file, which takes precedence over the system choice. Systems that chose fish among Genkan's applications before it came with Aizome keep it.
Programs built for other Linux distributions start as they would there. Editors and tools that download their own programs work without extra setup: Zed's language servers, debugger and AI agents, for example. These downloaded programs find the common libraries: the C and C++ runtimes, zlib, OpenSSL, curl, systemd and a few more. One that needs others, such as most graphical programs, still won't start, and neither will a script that asks for /bin/bash.
Tatami is Sekka's other desktop, for people who would rather tile windows and drive everything from the keyboard. It combines Hyprland with a compact bar, searchable application launcher and menus, notifications, display settings, and keyboard shortcuts. It takes inspiration from Omarchy and adapts the experience to NixOS. Genkan selects it beside Aizome; log in to it from the login screen, or leave it out when installing.
Choose a wallpaper under Style › Background. Style › Background settings lets you fill, fit, stretch, center or tile it, or use a solid color, with separate choices for each display. Wallpapers keep their original resolution; your display settings control any cropping.
For long downloads, builds, or overnight work, turn on Keep Awake using the coffee cup in the bar or Super + Ctrl + I. It prevents sleep, automatic screen locking, and lid-close sleep until you turn it off, and remembers your choice at your next login. You can still lock the screen yourself. A red coffee cup means protection could not be verified and needs attention.
To see what is using your computer, open Activity with Super + Ctrl + T. Each application shows with all its processes together, and you can sort them by processor, memory, estimated energy, graphics or disk use. Select one to watch everything about it change, or quit one that misbehaves. Its energy figures are estimates shared out from the processor's and graphics card's meters; the window says what it can and can't measure.
Laptop displays behave the way a Mac's do. Close the lid with an external display connected and the built-in display turns off, its windows move to the other screen, and the laptop keeps running; open the lid and the built-in display comes back where you arranged it. Unplug the last external display and the built-in display turns on. A display you turn off in Displays (Super + Ctrl + D) stays off whenever you reconnect the same displays, until you turn it on again or log in again. If a display change leaves a window off screen, Tatami brings it back, and Super + Ctrl + D always brings the Displays window to the screen you are using.
A display you set up in Aizome's Settings, such as one turned to portrait, comes up the same way in Tatami: its resolution, scale, rotation and place in the arrangement follow Aizome. Once you apply a change in Displays, every display that is on at the time keeps its own settings in Tatami from then on, and so does a display you scale with Super + /.
Docked, the laptop stays awake with its lid closed on battery power too. With no other display connected, closing the lid puts it to sleep, unless Keep Awake is on (then the built-in screen turns off). Lid handling and docking are in daily use with external displays, and virtual-machine tests with simulated displays and a simulated lid guard them between changes.
Sekka also enables USB keyboard and mouse wake paths, including their parent hubs. If moving the mouse doesn't wake a suspended computer, press a key or a mouse button.
See what's installed and why, find software, check for updates, return to an earlier generation, and free up store space. Everyday changes do not require editing Nix configuration by hand.
History shows, beside each older generation, the disk space deleting it would give back: only what nothing else keeps, since most of a generation is shared with the others and the running system. You can delete one from there, or tick any several, next to each other or not, and delete them together; the running one, the one the computer started with and the one selected for the next start stay. Ticked together, they show what deleting all of them frees, which can be more than their figures added up: generations next to each other share what a later update replaced. The space comes back when garbage is collected, which Yukimi can do right away. The figure is an estimate: on Btrfs with compression less may come back, and a program started from those files before the collection keeps them.
Every desktop uses Aizome's native Yukimi. It opens directly on Wayland and inside a nested Wayland window on X11. Commands use Ctrl in Tatami and the other desktops, and Super in Aizome.
Current application in Tatami, in a NixOS test VM.
Plasma, GNOME and Xfce are available too. Multiple installed desktops share your account and one login screen: Aizome's own when Aizome is installed, listing every desktop you chose, and GDM when GNOME is, since GNOME locks its screen only under GDM (calamares.loginScreen chooses otherwise).
This GNOME capture predates Yukimi's shared native interface.
Sekka ships as nightly ISOs for x86_64 PCs. An ISO is published only after that exact image has been installed and used in UEFI and BIOS virtual machines: installing, booting the installed system, logging in and using its desktops. That doesn't happen every night, so the newest ISO can be older than the newest update, and an installation catches up with its first update. Each published ISO joins the last seven on sekka.computer/download, with its checksum and the source revision it came from. GitHub's “Source code” archives are not bootable images.
To put a nightly on a USB drive, Kakehashi lists them, downloads and checks the one you pick, writes it, and reads every byte back, on Linux, macOS or Windows. On Sekka, install it from Yukimi → Discover; its macOS and Windows builds are GitHub workflow artifacts. Any tool that writes a raw disk image also works.
To build an image yourself, see DEVELOPERS.md. The image shows Sekka's boot splash (Esc shows the boot messages), then starts a live Aizome session with Genkan open. The boot menu also offers an older kernel and a recovery entry that draws the same Aizome session in software, without a GPU driver for NVIDIA graphics. Try the live desktop on your computer before you install.
Genkan offers ext4, Btrfs, or XFS, with UEFI or legacy BIOS boot. Optional RAM-sized swap and system tuning are enabled by default and can be switched off. Proprietary software is allowed by default with an opt-out; redistributable firmware may still be proprietary. The configured NVIDIA driver targets Turing and newer GPUs.
Native 4 KiB sector disks require booting the installation media in UEFI mode. Legacy BIOS installation requires 512-byte logical sectors, including 512e disks.
Open Yukimi → Updates → Update to get Sekka's newest nightly. It brings NixOS, the applications and the AI tools at the versions that nightly built and tested, and a nightly reaches you only once everything it needs is ready to download. An update never compiles software on your computer, except NVIDIA's driver, which is built for your kernel in a few minutes whenever either changes. CUDA builds you add yourself, such as llama.cpp's, download from the NixOS CUDA team's cache when it has them, and compile when it doesn't. If space runs short, Yukimi stops before the disk fills up and changes nothing. To update Sekka from a terminal, run:
sekka-updateEnter your administrator password when asked. Sekka downloads the update, builds your system, and applies changes safely. When a restart or sign-out is needed, Yukimi shows one completion message with a button to finish when you are ready. A restart also finishes desktop changes; you will not be asked to restart again for that same prepared update. Once preparation finishes, Yukimi can be closed: the computer starts the prepared system on its next boot. It never restarts or signs you out automatically. Adding or removing a desktop doesn't make an update wait for a restart; the login screen lists the change after your next one. An update that changes how the login screen starts a desktop still waits, since until then the login screen would start its previous version. Your account, installed applications, hardware configuration, and desktop choices stay in place. Previous generations remain available in Yukimi's History and the boot menu.
If your installation predates this command (including the original graphical installer builds), run this once:
nix run github:bitemyapp/sekka/nightly#updateThis also moves supported older installations from the separate Calamares, Tatami, and Yukimi repositories to Sekka. After restarting, the command and button above are available. If the build fails or you cancel before activation, the updater restores the configuration files it changed.
The terminal command and Yukimi's Update button do the same. Sources you have
pointed somewhere of your own keep their own rows and update separately, and
may need building. Run sekka-update --status to check whether anything
remains to be applied.
To get changes before the nightly does, turn on Early updates in
Yukimi's Updates page, or run sekka-update --early. Updates then
follow Sekka's main branch as soon as changes are merged, before the
nightly checks run, and anything the binary cache doesn't have yet builds on
your computer. sekka-update --nightly goes back.
Which desktops are installed, which one starts by default, the login
screen and the boot splash can be changed after installing too: in Aizome's
Yukimi → Desktops, or with sekka-update --choose, such as
sekka-update --choose calamares.loginScreen=aizome. Yukimi asks for your
password, builds the new system, and offers a restart when the change needs
one, as an update does.
To have the computer start straight into someone's account without asking for a password, pick them under Log in automatically as in Aizome's Settei → Users & Groups. Anyone with an account can be picked, including people you added after installing; someone added without a password has to set one first. Yukimi makes the change, which asks for an administrator password, and it applies from the next start, whichever login screen you use. Their saved passwords (the keyring) stay locked until their password is typed once. If the account can't be logged in to when the computer starts, the login screen shows instead.
Please open an issue with what you tried, what happened, and the image version or source revision. Hardware details help with boot and display problems. Review logs for personal information before attaching them.
To work on the distro, start with DEVELOPERS.md. Aizome, Tatami and Yukimi can also be used independently on NixOS through Sekka's individual modules.
Sekka builds on NixOS, Determinate Nix, and many other free-software projects. Genkan originated as the NixOS-focused Rust implementation in our Calamares fork. Aizome takes its ideas from Haiku, NeXTSTEP and IRIX; Tatami is inspired by Omarchy. Sekka is not an official NixOS, Determinate Systems, Calamares, or Omarchy product.
Components retain their own licenses and attribution: Genkan is GPL-3.0-or-later; Aizome, Tatami and Yukimi code is MIT OR Apache-2.0, with separately attributed configuration and artwork. See NOTICE, component provenance, and the license files in each component directory.