Fuzen

Think in Fuzen — learn functional programming with an embedded REPL. No setup, no memorization drills: write expressions, evaluate, and trace steps from the first screen.\n\n• Instant REPL (Playground)\n• Functional curriculum Phases 1–5\n• Step trace visualization\n• Tail-call optimization\n• Fully offline\n\nFree: Playground + Phases 1–2. One-time unlock for Phases 3–5.\n\nPrivacy: no account, offline, no ads.\nEULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/