cmarks is a free, open-source, read-only Markdown reader for macOS. It renders with GitHub's own cmark-gfm engine and stylesheet, so documents look exactly as they do on github.com: tables, alerts, math, Mermaid. Open a folder as a workspace, keep documents in tabs and splits like a terminal multiplexer, and when another app saves a file only the changed blocks update, scroll intact. Quick Look extension, Follow-Finder mode, Raycast extension. Homebrew tap or Mac App Store. MIT.
