Seelen-UI

Seelen UI is an open-source desktop environment replacement for Windows 10 and 11. It replaces native shell elements such as the taskbar, start menu, and notification flyouts with customizable alternatives. The software is available via the Microsoft Store, Winget, and GitHub releases, requiring the WebView runtime and Microsoft Edge to function correctly on the host system.

This application targets users who want to modify the visual identity and functional layout of their Windows desktop. It provides a set of primitives to build a minimal or feature-rich environment, utilizing a CSS and JSON based theming engine to control colors, fonts, and animations. Users can replace the standard Windows interaction model with a keyboard-first workflow that reduces reliance on the mouse.

Key features

• Tiling window manager with automatic layouts and configurable gaps
• Custom toolbar and macOS style application dock
• App launcher with fuzzy search for files and shell commands
• Dynamic accent color extraction from the current wallpaper
• Desktop widgets for system monitoring and media controls
• Virtual desktop implementation with unique wallpapers per workspace
• CSS and JSON based theming engine for shell elements
• Per-app rules for layout and workspace behavior
• Multi-monitor support with independent configurations

Built with Tauri, the software leverages web technologies to render its interface. It includes a Widget SDK that allows developers to create custom widgets using Svelte and TypeScript with full IPC access to system state. The window management system supports various layouts including BSP, columns, and stacks, while offering a floating mode to opt specific windows out of tiling. All configurations are stored in plain files, making the setup compatible with version control systems. The interface is localized in over 70 languages to support a global user base.

Seelen UI positions itself as a comprehensive shell replacement for Windows power users and designers.