mdformat-rs is an opinionated Markdown formatter for Rust, providing full CommonMark spec conformance with canonicalised output, GitHub Flavored Markdown support (tables, task lists, strikethrough, autolinks), and byte-for-byte preservation of YAML/TOML frontmatter.

The primary motivation is correct Unicode-width handling in GFM tables. Python mdformat is the behavioural reference for formatting decisions but does not render tables with Unicode-aware column widths, which mangles any table containing CJK text, emoji, or combining marks. mdformat-rs fixes that while remaining CLI-flag-compatible so editor integrations pointing at the Python tool work unchanged after switching binaries.

The project is a Cargo workspace with two crates: mdformat-rs (the embeddable library, no CLI dependencies) and mdformat-rs-cli (the thin binary wrapper). The library and CLI binary are not yet published to crates.io; build from source with cargo install --path crates/mdformat-rs-cli.