Babel vs Brython

Babel is a JavaScript compiler that converts modern syntax into code compatible with current and older browsers or other environments. Its transformation pipeline is built from plugins, which users can combine into presets or write themselves. Babel provides transformers for the latest JavaScript and a React preset for JSX. It can also add features through third-party polyfills such as core-js, run codemods, and remove Flow or TypeScript type annotations; it does not check types. Source maps support debugging compiled output. The command-line interface can compile files or directories, watch for changes, and generate source maps. Installation documentation covers npm, Yarn, pnpm, and Bun. A standalone build can run in browsers and other non-Node.js environments, including on scripts marked text/babel or text/jsx, but the documentation recommends ahead-of-time transpilation with a Node.js build system for production. Babel is free, MIT-licensed, community-funded, and maintained by volunteers. The project directs support questions to GitHub Discussions, Slack, Stack Overflow, or Bluesky.

Brython has no write-up on Specifiction yet; its figures are above.