Motivation

Why Penmark exists, what gap it’s filling, and what it unlocks once it does. To be fleshed out.

Why one engine

The shape of the existing ecosystem — Tatham’s collection, PuzzleKit, per-puzzle solvers, SudokuPad, pzv.jp, F-Puzzles — and what none of them cover end-to-end.

Why now

What changed: Rust + WASM let one codebase serve CLI, desktop, and browser without rewrites; modern CSP techniques handle this catalog cleanly; large public puzzle datasets exist to mine.

What this enables

The tools, datasets, and feedback loops Penmark makes possible once the core engine is real — authoring, generation, grading, discovery, cross-genre infrastructure.

Non-goals

What’s intentionally out of scope, so scope creep has somewhere to be pushed back against.