Open source. Open possibilities.

Marked is a fast, lightweight Markdown parser and compiler that works in browsers, on Node.js servers, and via CLI. It supports all standard Markdown features, custom extensions, and is easily adaptable for different use cases.

Pandoc is a universal markup converter that functions as both a Haskell library and a command-line tool for converting documents between a wide variety of markup formats.

remark is a plugin-driven markdown processor from the unified collective. It parses markdown into an AST (mdast), lets plugins inspect and transform it, and serializes it back, with 150+ plugins and a CLI for linting and formatting.