marked is a high-performance Markdown parser and compiler written in TypeScript, designed for speed and extensibility. It converts Markdown text into HTML, supporting the CommonMark specification and GitHub Flavored Markdown (GFM) extensions such as tables, task lists, strikethrough, and autolinks. The library is used both as a Node.js package (ESM and UMD builds) and as a command-line tool (bin/marked). Its architecture is modular, consisting of a Lexer (tokenization), Parser (AST construction), Renderer (HTML output), and an extension system via Hooks and custom tokenizers. The core entry point is the `marked()` function, which accepts a Markdown string and options, and returns HTML. The library also exposes a `Marked` class for more control, including async parsing, token walking, and plugin integration. marked does not sanitize output HTML, leaving XSS prevention to downstream consumers. The project includes an extensive test suite with over 600 CommonMark spec examples, GFM spec tests, and custom regression/performance tests (including ReDoS mitigation). The CLI supports stdin, file input, and config files, making it suitable for scripting and build pipelines.
react-native-nitro-markdown is a high-performance native Markdown parser and renderer for React Native, built on a vendored md4c C library (forked as nitromd) and the Nitro Modules framework for direct JSI bridging. It provides full CommonMark and GitHub Flavored Markdown support, plus extensions for LaTeX inline/block math, task lists, and strikethrough. The library offers three primary consumption modes: a full `<Markdown>` React component with customizable renderers, a `<MarkdownStream>` component designed for progressive rendering of streaming text (e.g., from LLM output), and a headless API (`parseMarkdown`, `extractPlainText`, `createMarkdownSession`) for server-side or non-React usage. Architecture is layered: native C++ parser produces a typed JSON AST, which is consumed by a React rendering pipeline with caching, incremental updates, and a plugin system. The repository includes a comprehensive test suite (unit, conformance, snapshot, C++ unit, E2E Maestro), performance benchmarks, fuzz testing, and a CI/CD pipeline for automated releases. It is a mature, well-engineered library with strong focus on correctness, performance, and developer experience, though it is tightly coupled to the iOS/Android native runtime and Nitro Modules ecosystem.