MarkForge

A native macOS Markdown viewer (with an editor on the roadmap), built in Rust on GPUI — Zed's GPU-accelerated UI framework — and the gpui-component widget library.

No web view, no Electron. The Markdown is rendered by the same engine that powers Zed's own preview.

Features

• Native & fast — GPU-accelerated rendering, instant startup.
• File explorer — VSCode-style sidebar (⌘B). Open a folder (⌘⇧O), browse the tree, click any file to open it.
• Viewer + editor — read full-width, or ⌘E into a resizable split with a syntax-highlighted Markdown source editor and live preview.
• JSON too — open .json/.jsonc files: minified JSON is pretty-printed, the editor switches to JSON highlighting, and the preview shows a highlighted code view.
• docx · hwpx · pdf — read-only import: Word/HWPX documents convert to Markdown (headings, emphasis, lists, tables), PDFs to extracted text. ⌘S saves a Markdown copy — originals are never overwritten.
• Live reload — edit the file in any other app and MarkForge updates it automatically (mtime-polled in the background); debounced so typing stays smooth.
• Zoom — ⌘+/⌘-/⌘0 scales both editor and preview (body, headings, code).
• Theme — light (default), dark, or follow the macOS system appearance.
• Recent files — File ▸ Open Recent.
• Persisted settings — theme, zoom, and recent files are remembered across launches.
• Open anywhere — file dialog, drag-and-drop, or a command-line argument.

Website: https://rescenedev.github.io/markforge/

Install

# Homebrew (recommended)
brew install --cask rescenedev/tap/markforge

Or grab MarkForge.app from the latest release.

Usage

# Run with the bundled sample document
cargo run --release

# Open a specific file
cargo run --release -- path/to/notes.md

# Build a distributable macOS .app bundle (→ target/release/MarkForge.app)
./scripts/bundle.sh

Shortcuts

Action	Key
Open file	⌘O
Open folder	⌘⇧O
Toggle sidebar	⌘B
Save	⌘S
Settings	⌘,
Toggle editor	⌘E
Zoom in / out / reset	⌘+ / ⌘- / ⌘0
Reload	⌘R
Toggle light/dark	⌘⇧L
Navigate file tree	↑ ↓ (move) · ← → (collapse/expand) · ⏎ (open)
Close window	⌘W
Quit	⌘Q

You can also drag a .md file onto the window to open it (or drag a folder to open it in the sidebar). Closing, quitting, opening another file, or reloading with unsaved edits asks to save first.

Settings live at ~/Library/Application Support/MarkForge/settings.json — ⌘, opens that file in MarkForge itself; save (⌘S) and the changes apply instantly. Keys include theme, zoom, body_font_size, preview_font, editor_font, syntax_theme, sidebar_open, preview_padding, backdrop_opacity (0.2–1.0 window-gradient transparency), git_auto_commit (commit on every save, note-vault style), and sidebar_bg_dark.

Building

Requires a recent stable Rust toolchain (edition 2024 → Rust ≥ 1.85) and the Xcode Command Line Tools.

cargo build --release

The first build compiles GPUI and a large dependency graph from source, so it takes a while. Subsequent builds are incremental and fast.

Roadmap

• Markdown viewer
• Live reload
• Drag-and-drop + file dialog
• Split-pane editor with live preview
• Syntax-highlighted source editing
• Content zoom
• Light / dark / system theme + persisted settings
• Recent files
• File-explorer sidebar (open folder, tree navigation)
• Tabs / multiple open documents
• .app bundle + Finder file association
• Outline (table of contents) sidebar
• Export to PDF / HTML

Project layout

src/
  main.rs     # app bootstrap: actions, menus, key bindings, window
  app.rs      # MarkForge view: title bar, sidebar, editor/preview, zoom, watcher
  file_tree.rs# file-explorer model (open folder, expansion, listings)
  rem_scaled.rs # element wrapper that scales `rem` for the editor zoom
  settings.rs # persisted settings (theme, zoom, fonts, recent files)
assets/
  sample.md   # bundled showcase document

License

MIT.