# Third-party software

- **Stockfish 19**, official Stockfish contributors, GPL-3.0. Downloaded from https://github.com/official-stockfish/Stockfish/releases/tag/sf_19. The upstream archive contains the complete corresponding engine source in `vendor/stockfish/src`, license in `vendor/stockfish/Copying.txt`, authors, networks and build instructions. `npm run setup:engine` retrieves the same release and checks its published SHA-256. Engine runs as a separate UCI process. Keep this source and license with any redistributed engine binary. https://stockfishchess.org/
- **Cburnett chess pieces**, Colin M. L. Burnett, GPL-2.0-or-later. SVG source in `public/pieces`, retrieved from https://github.com/lichess-org/lila/tree/master/public/piece/cburnett. License attribution: https://github.com/lichess-org/lila/blob/master/COPYING.md. GPL-3.0 text is included; redistribution under GPL-3.0 is permitted by the “or later” option.
- **chess.js**, BSD-2-Clause; **Express**, MIT; **Socket.IO**, MIT; **better-sqlite3**, MIT; **gifenc**, MIT; **helmet**, MIT; **express-rate-limit**, MIT. Versions and source packages are locked in `package-lock.json`; original license files are distributed by npm in each package directory.
- **Playwright**, Apache-2.0, development/testing only.
- **Gemma 4 E2B and 12B**, Google, Apache-2.0 model weights. Downloaded by Ollama into `data/models`, not committed. Official model: https://deepmind.google/models/gemma/gemma-4/; runtime tags: https://ollama.com/library/gemma4:e2b and https://ollama.com/library/gemma4:12b. The installed model's license can be inspected with `OLLAMA_HOST=127.0.0.1:11436 vendor/ollama/bin/ollama show gemma4:e2b --license`.
- **Ollama 0.40.13**, MIT, isolated optional local runtime under `vendor/ollama`. https://github.com/ollama/ollama/releases/tag/v0.40.13
- **Node.js 22.23.4**, Node.js contributors, licenses included in the optional downloaded runtime under `vendor/node-v22.23.4-linux-x64`.

JAVI does not use third-party fonts, trackers, advertising, remote piece images, or paid inference APIs. The original daily studies are maintained in `server/puzzles.js` and verified by Stockfish in tests.

## Original Mission 002 assets

The Persian, Spartan, Crusader, Ayyubid, Aurora and Umbra SVG armies, clock decorations and world environments are original JAVI vector artwork, distributed under the project GPL-3.0 license. Editable sources and generator are in `public/worlds/`; see `public/worlds/README.md`. No stock photographs, scraped character art or remote asset services are used. The original interactive lessons are in `public/lessons.js`; daily studies are in `server/puzzles.js`.

## ROOKVERSE 2.1

The Assyrian/Babylonian armies, Mesopotamian environment and role-silhouette revisions are original GPL-3.0-or-later vector art (`public/worlds/role_shapes.py`). The existing royal crown has been reused with a king insignia and matching simplified icons. Its supplied visual reference was https://thelionandthesun.org/file/2025/02/Pahlavi-crown-main.jpg ; the photograph is not redistributed. Professor JAVI and VAZIR remain the product's characters.

## Cloud runtime chess engine

Production uses Stockfish.js 19.0.1, single-threaded Lite WASM, by Chess.com / Nathan Rugg and the Stockfish contributors (GPL-3.0). Source and build instructions: https://github.com/nmrugg/stockfish.js/tree/v19.0.1 . The upstream npm archive is https://registry.npmjs.org/stockfish/-/stockfish-19.0.1.tgz . The Workers adapter extracts the Emscripten factory and disables its Node/browser loader, supplying a statically imported WASM module. The WASM bytes are unchanged. License: `deploy/cloud/vendor/COPYING`. The Lite network and CPU-bounded search differ from full native Stockfish.