HongDown

Hongdown is a free, open-source Markdown formatter that automatically applies Hong Minhee's Markdown style conventions. Written in Rust, it uses the Comrak parser to process documents while preserving Markdown structure. It standardizes formatting across headings, paragraphs, lists, code blocks, and other Markdown elements. Users can format individual files, multiple documents, or entire directories recursively. A checking mode identifies files that violate formatting rules without modifying them. Its diff mode previews changes before they are applied. Configurable options include line width, code fence characters, and MDX processing. Hongdown integrates with editors and automation workflows and offers reusable Rust and WebAssembly libraries for application development.