License & credits
This 924-puzzle library uses Towers generation from Simon Tatham’s Portable Puzzle Collection, official archive puzzles-20260923.616da16. The archive and its short release identity are verified. The full upstream Git object remains unverified after a recorded HTTP 403; no alternate-source verification is claimed.
The clues were generated offline, solved freshly without the generated answer, independently checked for exactly one solution, and deduplicated under all eight rotations/reflections for both clues and answers. The preserved source package contains the archive, native adapter, exact validator and provenance. Those tools and answers are not served with this game.
Profiles: 24 × 4×4 Easy; 300 each of 5×5 Easy, 5×5 Hard and 6×6 Easy. These are upstream generator tiers, not calibrated human difficulty. The browser UI and skyline cover are code-native, without external art, fonts or runtime requests. Progress stays in a separate browser-local database; there is no cloud sync.
Upstream MIT license
This software is copyright (c) 2004-2024 Simon Tatham. Portions copyright Richard Boulton, James Harvey, Mike Pinna, Jonas Kölker, Dariusz Olszewski, Michael Schierl, Lambros Lambrou, Bernd Schmidt, Steffen Bauer, Lennard Sprong, Rogier Goossens, Michael Quevillon, Asher Gordon, Didi Kohen, Ben Harris and Anders Höglund. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.