# Seelen UI: a Windows 11 shell replacement built on Tauri and Rust > Seelen UI replaces the Windows taskbar, Start menu, dock and window manager with a CSS/JSON-themable shell. It is a real desktop environment, not a skin, and that is exactly why the install and uninstall paths matter. **eythaann/Seelen-UI** — The Fully Customizable Desktop Environment for Windows 10/11. Whether you want a minimal, distraction-free setup or a feature-rich power-user environment, Seelen UI gives you the primitives to build it. - Repository: https://github.com/eythaann/Seelen-UI - Stars: 17,883 · Forks: 609 - Language: Rust - License: AGPL-3.0 - Published: 2026-08-04 · Updated: 2026-08-18 · Language: en - Canonical page: https://hysenlabs.com/projects/eythaann-seelen-ui ## What Seelen UI replaces, and who that is for Seelen UI is not a theme pack. The README calls it "a full desktop environment replacement for Windows", and the feature list backs that up: the taskbar, dock, app launcher, window manager, notification flyouts and virtual desktops are all candidates for replacement. If you only wanted different icons and a translucent taskbar, this is more machinery than you need. The audience is narrower than the marketing suggests. Someone who wants a minimal, distraction-free desktop and someone who wants a dense power-user environment are both served, but they are served by the same primitives: a CSS/JSON theming engine, a plugin widget system and per-app rules. That means the product is a toolkit. You get the pieces and you assemble the desktop. The README says it is available in 70+ languages, which matters if you share the machine with people who do not read English. The project is written in Rust, with a Tauri-based frontend, and is licensed AGPL-3.0. That licence choice is worth noting before you read further: it is a strong copyleft licence, and it governs the project as distributed. ## The architecture: a Rust host, a Tauri webview, and CSS as the theming layer The workspace layout in Cargo.toml tells you how the project is split. There is a core library at libs/core, an IPC library at libs/slu-ipc, a positioning library at libs/positioning, a macro crate at libs/slu-macros, utility code at libs/utils, the main application under src, and a src/hook_dll member that implies a native hook component loaded into other processes. The frontend lives alongside it: package.json pulls in Tauri 2.x, Preact, signals, Svelte tooling, flexsearch and react-router. That mix is the mechanism. Native Rust code owns the Windows integration (window management, hotkeys, screenshots, system information, the Windows API bindings in the workspace dependencies). The user interface is web technology rendered in a webview, which is why the theming engine can be CSS and JSON rather than a bespoke skin format. Scoped CSS styles shell elements; JSON carries configuration. Widgets are rendered on the desktop layer, and the README describes per-widget theming, so each widget can carry its own style independently. The tiling window manager is the part that changes how you work rather than how things look. The README lists BSP, columns and stacks as layout options, with configurable inner and outer gaps, floating mode for opting individual windows out, and per-app rules for layout, workspace and floating behaviour. A custom Alt+Tab replaces the native task switcher. Virtual desktops are reimplemented rather than borrowed, with a workspaces viewer, per-workspace wallpapers and named workspaces. The cost of this architecture is that you are running a webview-based shell on top of Windows. The README does not publish memory figures, startup times or any benchmark, so there is no number to quote here. Treat performance claims from anywhere else as unverified. ## Installing Seelen UI and a first configuration The README points at two distribution channels: the Microsoft Store listing (apps.microsoft.com, Seelen UI, id 9p67c2d4t9fb) and the GitHub releases page. The Store listing is the lower-friction path if you want updates handled for you. The releases page carries versioned builds, with v2.8.2 dated 2026-08-03 and v2.8.1 dated 2026-07-27, plus a nightly channel whose most recent entry is dated 2024-10-13. If you build from source instead, the repository is a Cargo workspace with a Node frontend. The package.json defines the scripts. Note the preinstall hook: it runs the core library build before dependencies install, so the order is not optional. ```bash npm install ``` The preinstall script runs `npm run build:lib`, which changes into `./libs/core` and runs `deno task build`. That means Deno has to be available before npm install will succeed. The postinstall script then runs `lefthook install`. For a development run, the package.json defines a single command that compiles the Rust side first: ```bash npm run dev ``` That expands to `cargo build && tauri dev`. Type checking is separate and spans three tools: ```bash npm run type-check ``` Once Seelen UI is running, the README describes settings as one unified place for themes, layouts, keybindings, widget positions, workspace rules and per-app overrides, with live preview. That is the first thing to open. The app launcher is described as keyboard-driven and inspired by Rofi, with fuzzy search; the README does not document its default keybinding, so check the settings interface rather than guessing. For themes, the README states that Seelen UI ships a theming engine covering colors, fonts, borders and animations, and that community themes can be installed. It also describes a dynamic accent color that analyzes the current wallpaper and derives an accent automatically. The README does not give the JSON schema for a theme file, so the settings interface and the documentation directory in the repository are where to look next. ## Where Seelen UI breaks down The first limitation is the one the README is quietest about: removal. Search interest in uninstalling Seelen UI is high enough that "Seelen UI uninstall" and "how to get rid of seelen UI" both appear in the query data, yet the README documents replacement far more thoroughly than restoration. A shell that replaces the taskbar, Start menu, flyouts and virtual desktops sits close to the parts of Windows people rely on when something goes wrong. Decide how you will revert before you install, not after. The second is maintenance cadence. The last push to the repository was on 2024-10-13, which is the same date as the nightly release. Versioned releases continued afterwards, with v2.8.2 on 2026-08-03, but the repository activity and the nightly channel have not moved since that October date. If you depend on nightly builds, you are depending on something that has not been refreshed in a long time. The third is the nature of the tool. A tiling window manager with per-app rules is a commitment. Every application that misbehaves under tiling needs a rule, and every rule is something you own. On a locked-down corporate machine, or one where IT controls the shell, this is the wrong tool entirely. It is also the wrong tool if you want the Windows experience to stay recognisable to other people who use the same account. Finally, the README describes a settings interface, a theming engine, a widget system and dozens of features without stating system requirements, supported Windows builds beyond 10 and 11, or any performance figures. That silence is not evidence of a problem, but it does mean you cannot size the change from the README alone. ## Seelen UI against the alternatives people search for The common comparison is with shell customisation tools that patch or extend the existing Windows shell rather than replacing it. Those tools typically leave the taskbar, Start menu and window manager in place and modify their appearance or add behaviour on top. The difference in approach is structural: extending the shell means Windows remains the owner of window management and virtual desktops, while Seelen UI takes those responsibilities itself, which is why it can offer BSP and column tiling layouts, a reimplemented Alt+Tab and per-workspace wallpapers that those tools generally cannot. The trade is surface area. A tool that extends the shell breaks in a narrower set of ways. Seelen UI, because it owns the taskbar, the dock, the launcher, the flyouts and the desktop layer, has more places to fail when Windows changes underneath it, and more places for you to configure. If what you actually want is a themed taskbar and a Start menu replacement, the smaller tool is the better fit. If you want keyboard-driven tiling, a Rofi-style launcher and widgets rendered on the wallpaper layer, the extending tools are not in the same category. The README's own framing supports that reading: it says the launcher is inspired by Rofi, which is a Linux launcher, and the tiling layouts it lists are borrowed from the tiling window manager tradition rather than from Windows shell tweakers. ## Licence, upgrade path and what you are taking on Seelen UI is AGPL-3.0, and package.json states AGPL-3.0-or-later. This is a strong copyleft licence. If you run it as a desktop environment for yourself, the practical effect is minimal. If you fork it, redistribute a modified build, or offer a modified version as a network service, the licence obligations become relevant. This is not legal advice; read the LICENSE file in the repository and the CLA.md and CONTRIBUTING files if you intend to contribute. Upgrade cost depends on channel. Store installs follow the Store's update mechanism. Release installs follow the versioned tags, and the gap between v2.8.1 and v2.8.2 is about a week, which suggests a steady release cadence even while the repository's last push date sits at 2024-10-13. The nightly channel is the one to avoid unless you intend to track breakage, given its last entry is dated 2024-10-13. The hidden cost is your configuration. Themes, keybindings, widget positions, workspace rules and per-app overrides accumulate over time, and the README does not document a migration or export path for them. Budget for rebuilding that configuration after a major version jump. The repository also ships a changelog.md, a documentation directory, a SECURITY.md and a crowdin.yml for translation contributions. Those are the files to read before filing anything. ## Conclusion Adopt Seelen UI if you treat your Windows desktop as a configurable surface and are willing to maintain that configuration yourself; the theming engine, tiling layout and per-app rules are the reason to switch. Do not adopt it on a machine you cannot afford to troubleshoot, and do not expect the README to walk you through removal. Before installing, open the Microsoft Store listing or the GitHub releases page for v2.8.2, confirm your Windows build, and read the uninstall question below, because the README documents what Seelen UI replaces far more thoroughly than how to put Windows back. ## FAQ ### Is Seelen UI safe to use? The repository is public, licensed AGPL-3.0, and distributed through the Microsoft Store and GitHub releases. The README does not make security claims, and the project ships a SECURITY.md, so the security posture is documented in the repository rather than in the README. ### What is Seelen UI? It is a full desktop environment replacement for Windows 10 and 11, not a theme pack. According to the README, the taskbar, dock, app launcher, window manager, notification flyouts and virtual desktops can all be replaced, restyled and extended. ### Is Seelen UI free? The project is licensed AGPL-3.0 and package.json states AGPL-3.0-or-later. The README points to the Microsoft Store and to GitHub releases as the distribution channels; it does not describe a paid tier. ### How to get rid of Seelen UI? The README does not document rollback or removal. Installation is described through the Microsoft Store listing and GitHub releases, so uninstalling follows the same channel you installed from, but the project itself gives no removal steps. ### How to install Seelen UI? The README lists two routes: the Microsoft Store listing (Seelen UI, id 9p67c2d4t9fb) and the GitHub releases page. Building from source is a Cargo workspace with a Node frontend, where npm install triggers a preinstall build of libs/core through Deno. ### How to use Seelen UI with Wallpaper Engine? The README does not mention Wallpaper Engine. It does describe a dynamic accent color that analyzes the current wallpaper, desktop widgets rendered on the wallpaper layer, and a separate wallpaper per workspace, but nothing about third-party wallpaper applications. ## Sources - [Official README](https://github.com/eythaann/Seelen-UI#readme) - [Project repository](https://github.com/eythaann/Seelen-UI) - [Release notes](https://github.com/eythaann/Seelen-UI/releases) --- Hysen Labs editorial analysis, written from the project's own repository and release notes. Cite the canonical page: https://hysenlabs.com/projects/eythaann-seelen-ui