A macOS viewer and editor for the documents you keep. Warm cream stock, a serif at a fixed reading measure, and GitHub-flavored rendering done entirely offline. No network, no telemetry, no account.
Requires macOS 14
Every part of it answers a question a markdown reader actually runs into.
Every colour in the app is a token, and the token's name is the CSS custom property the preview page reads - so the window chrome and the document are never two palettes pretending to be one. Body text is held to 7:1 contrast against its own background by the test suite, which is why the ported schemes are lifted rather than copied.
The pane toggles are Option-Command, because a menu shortcut is matched before the responder chain and plain Cmd-V would have taken Paste out of the editor.
Downloads the latest build and installs it to /Applications.
On first launch the app writes a md-boss command into ~/bin, so md-boss . opens the current folder in the sidebar.
SwiftPM and a hammer file, no Xcode project. Needs macOS 14, a Swift 6.2 toolchain and swiftlint.