The React runtime of this site's React parts, built by scripts/learn-js/react-bundle.mjs from these npm packages: - react 19.3.0 (MIT, LICENSE-react.txt) - react-dom 19.3.0 (MIT, LICENSE-react-dom.txt) - scheduler 0.28.0 (MIT, LICENSE-scheduler.txt) - @testing-library/react 16.3.3 (MIT, LICENSE-testing-library-react.txt) - @testing-library/dom 10.4.2 (MIT, LICENSE-testing-library-dom.txt) - @testing-library/user-event 14.6.7 (MIT, LICENSE-testing-library-user-event.txt) react-core.mjs and react-testing.mjs hold the packages' files (React, React DOM and scheduler: their development builds; @testing-library/dom and @testing-library/react: their UMD builds; @testing-library/user-event: its CommonJS files), unmodified except that require() names are resolved and source-map comments removed; @testing-library/dom's UMD build contains its own dependencies (see its package for their licences). The define()/require() wrapper and the small facade modules (react.mjs, react-dom-client.mjs, ...) are the site's own code. Sources: https://github.com/facebook/react, https://github.com/testing-library