Astal is a collection of GObject-based libraries for building Wayland desktop shells and widgets on Linux. It provides reactive primitives (Variable, Binding) for declarative state management, along with wrappers for system services like NetworkManager, UPower, Bluetooth, MPRIS, audio (WirePlumber), system tray, and compositor-specific protocols (Hyprland, River, ext-workspace). The framework supports multiple frontend languages (GJS/TypeScript, Lua, Python) and both GTK3 and GTK4 via separate library targets. Examples demonstrate complete status bars and widget systems. The architecture is modular: core reactive abstractions live in `lang/gjs` and `lib/astal/io`, while domain-specific libraries under `lib/` expose GObject signals and properties for hardware and desktop services. Build system is Meson with Vala/C sources, GObject Introspection for bindings, and Nix flake for reproducible packaging. The documentation site uses VitePress. The project is actively maintained but in early development (v0.1.0 WIP). It shows strong engineering practice with well-structured reactive patterns and clean GObject usage, though there is duplication across language bindings and some deprecated APIs remain (e.g., AstalIO.Variable). The codebase is feature-rich and immediately usable for building custom Linux desktop environments.