A reactive, functional language for the Linux desktop

Write desktop apps where the compiler catches your mistakes, the runtime handles your reactivity, and the architecture stays clear.

🧊 No Mutation, No Surprises

Values never change. State flows through signals. You always know what a name refers to — now and forever.

Signals are language primitives, not a library. Dependencies are proven at compile time. The runtime does the minimal work.

Markup targets GTK4 and libadwaita directly. Type-checked attributes, signal-driven updates, no web runtime.

Closed types, exhaustive pattern matching, no null. Domains prevent mixing up durations with integers, URLs with text.

No if/else, no loops. Pipe algebra makes data flow visible, composable, and exhaustively checked.

All external I/O enters through typed Sources. Your code is pure by default. Effects are declared, never hidden.