Arto — the Art of Reading Markdown.

A local app that faithfully recreates GitHub-style Markdown rendering for a beautiful reading experience.

Markdown has become more than a lightweight markup language — it's the medium for documentation, communication, and thinking in the developer's world. While most tools focus on writing Markdown, Arto is designed for reading it beautifully.

The name "Arto" comes from "Art of Reading" — reflecting the philosophy that reading Markdown is not just a utility task, but a quiet, deliberate act of understanding and appreciation.

Arto faithfully reproduces GitHub's Markdown rendering in a local, offline environment, offering a calm and precise reading experience with thoughtful typography and balanced whitespace.

• GitHub-Style Rendering — Accurate reproduction of GitHub's Markdown styling with full support for extended syntax
• Native Performance — Built with Rust for fast, responsive rendering
• Auto-Reload — Automatically updates when the file changes on disk
• Offline First — No internet connection required — read your docs anytime, anywhere

• File Explorer — Built-in sidebar with file tree navigation for browsing local directories
• Quick Access — Bookmark frequently used files and directories for instant access
• Directory History — Back/forward navigation within the sidebar file explorer
• Table of Contents — Automatic TOC panel for easy document navigation
• Live Navigation — Navigate between linked markdown documents with history support (back/forward)

• Find in Page — Search within documents with Cmd+F
• Pinned Search — Pin search queries with persistent multi-color highlighting across sessions

• Tab Support — Open and manage multiple documents in tabs within a single window
• Multi-Window — Create multiple windows and open child windows for diagrams
• Cross-Window Tabs — Drag and drop tabs between windows
• Drag & Drop — Simply drag markdown files onto the window to open them

• Mermaid Diagrams — Interactive diagram viewer with zoom, pan, and copy-as-image
• Math Expressions — Beautiful KaTeX rendering for mathematical notation
• Code Highlighting — Syntax highlighting with copy button for code blocks
• Frontmatter — Renders YAML frontmatter as a styled, collapsible table
• GitHub Alerts — Full support for NOTE, TIP, IMPORTANT, WARNING, and CAUTION alerts

• Dark Mode — Manual and automatic theme switching based on system preferences
• Zoom Controls — Keyboard shortcuts and trackpad gestures for zoom
• Preferences — Configurable settings for sidebar, TOC, and more
• Context Menus — Right-click menus for quick actions on files and content

Use Homebrew tap to install. Since the application is not signed or notarized with an Apple Developer ID, you'll need to remove the quarantine attribute after installation. See homebrew-tap for more information.

brew install --cask arto-app/tap/arto
xattr -dr com.apple.quarantine /Applications/Arto.app

Alternatively, Nix is also supported. To try it without a permanent installation:

nix run github:arto-app/Arto

For a permanent installation, use nix-darwin or home-manager. Add the following to your flake inputs:

arto.url = "github:arto-app/Arto";

Then add it to environment.systemPackages (nix-darwin) or home.packages (home-manager):

environment.systemPackages = [ inputs.arto.packages.${system}.default ];

Launch the application to see the welcome screen with keyboard shortcuts and usage instructions.

After installation, the arto command becomes available in your terminal:

arto                     # Launch Arto (shows welcome screen)
arto README.md           # Open a specific file
arto docs/               # Open a directory in the file explorer
arto file1.md file2.md   # Open multiple files in tabs

Arto runs as a single instance — if Arto is already running, the command sends paths to the existing process instead of launching a new one. Files and directories open in new windows, while running arto without arguments shows the main window if it's hidden.

Visit arto-app.github.io for screenshots, feature highlights, and more.

See CONTRIBUTING.md for development setup and guidelines.

See LICENSE file for details.