MarkOne

MarkOne is a lightweight Markdown viewer and editor for macOS.

It is built for opening Markdown files quickly, reading them in a clean rendered preview, making focused edits, and exporting polished PDFs without setting up a workspace or library.

Use MarkOne for README files, notes, documentation drafts, project plans, and any plain-text Markdown document you want to view or adjust with native Mac controls.

Highlights:
- Fast native macOS document experience
- Clean rendered Markdown preview
- Simple edit and split-view modes
- PDF export for sharing finished documents
- Light, dark, sepia, and system-aware reading appearance
- Quick Look preview support for Markdown files
- Plain file-based workflow with no accounts, sync, or project setup

MarkOne keeps the source Markdown intact and stays out of the way, so you can move from file open to reading or editing immediately.