react-syntax-highlighter is a React component library for syntax highlighting that supports two major backends: highlight.js (via lowlight) and Prism (via refractor). It renders syntax-highlighted code into React virtual DOM with inline styles, avoiding `dangerouslySetInnerHTML`. The architecture is built around a core highlighter factory in `src/highlight.js` that takes an AST generator and produces `<pre>`/`<code>` structures with optional line numbers, line wrapping, custom renderers, and style injection. The library provides both statically bundled builds (all languages included) and light/async variants that support dynamic language registration and code splitting via Webpack's `import()` comments. This enables consumers to reduce bundle size by loading only the languages they need, both synchronously and asynchronously. Beyond the core highlighter, the repository includes a massive collection of auto-generated theme and language files—over 90 highlight.js themes and 40+ Prism themes, plus hundreds of language definitions—all exported as JavaScript objects. Build scripts in `scripts/` generate these assets from upstream packages, ensuring theme CSS is parsed and camel-cased into inline style objects. The library also exports a `createElement` utility and a `checkForListedLanguage` helper, and supports custom renderer plugins (e.g., virtualized rendering for large blocks of code). Although the codebase is functionally complete and well-tested, it suffers from moderate technical drift due to outdated dependencies, lack of TypeScript definitions, and a fragile generated file structure that is tightly coupled to specific versions of highlight.js and prismjs.