A lightweight, native macOS Markdown reader and editor. No Electron — built with Swift + SwiftUI.

• Full GFM support — tables, task lists, strikethrough, fenced code blocks, autolinks
• Edit / Preview mode per tab (⌘⇧P to toggle)
• Vertical sidebar with document list — like Notes or ChatGPT
• Horizontal tab bar with favicon-style letter badges
• Table of contents — click the ▶ triangle in the sidebar to expand a document's headings; click any heading to jump to it in the editor or preview
• Favicon letter — the first letter of the H1 heading shown in both sidebar and tab bar
• Drag and drop — drag any .md file onto the app window to open it; title-bar proxy icon for macOS-native drag behaviour (Cmd+click to see path)
• Full keyboard shortcuts on-par with macOS TextEdit (see below)
• Syntax highlighting in the editor (headings, bold, italic, code, links, blockquotes, tables…)
• Light and dark mode preview — automatically follows System Appearance

• macOS 14.0 (Sonoma) or later
• Xcode 16 or later

git clone https://github.com/YOUR_USERNAME/Markfops.git cd Markfops xcodegen generate # generates Markfops.xcodeproj open Markfops.xcodeproj # then press ⌘R

First run: Xcode will resolve Swift Package dependencies (libcmark_gfm, swift-collections) automatically. This requires an internet connection on the first build.

Markfops/ ├── App/ — Entry point, AppDelegate ├── State/ — Document, DocumentStore, EditMode, HeadingNode ├── Views/ — All SwiftUI views (sidebar, tab bar, editor container…) ├── Editor/ — NSTextView subclass + syntax highlighter ├── Renderer/ — cmark-gfm HTML renderer + HTML template ├── Parsing/ — Heading parser (for TOC + favicon letter) ├── Commands/ — Keyboard shortcuts via CommandMenu └── Resources/ — CSS stylesheets, asset catalog 

MIT — see LICENSE for details.