Sudoku engine
  sudokuJS 0.4.4
  https://github.com/pocketjoso/sudokuJS
  Commit c7221994ecc12a68ef3ba97ac125da1b18c1a4b9
  Author: Jonas Ohlsson
  License: MIT
  The file header in sudokuJS.js states the MIT license.
  Local edits in that file: generation is called with a difficulty
  string, unfinished grids are not accepted, a house duplicate in
  the first cell is rejected, and generation stops after 16 tries
  or a time budget. sudokuJS.css is the author's
  original stylesheet and is kept with the engine. The page uses
  games/sudoku/sudoku.css for the Mr. E Science layout.

MIT License

Copyright (c) Jonas Ohlsson

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.

jQuery 3.7.1
  https://jquery.com/
  Copyright OpenJS Foundation and other contributors
  License: MIT
  The license notice is in the header of jquery.min.js.
  Hosted locally so the game does not call a CDN.