A fast, native macOS Markdown viewer with streaming support. Pipe Markdown to it, open a file directly, or launch an empty window for quick previews. Built with cacao and pulldown-cmark.

• Native macOS GUI (AppKit/WebView)
• Live streaming: Pipe Markdown to stdin and see live updates
• Open files directly: Pass a markdown file as an argument to view it instantly
• GitHub-flavored Markdown: Tables, footnotes, strikethrough, task lists
• Mermaid diagram support: Interactive flowcharts, sequence diagrams, and more
• LaTeX/Math rendering: KaTeX support for mathematical expressions
• External link handling: Opens links in your browser
• Customizable appearance: Font family, size, and theme preferences

Download the latest release for your platform from the releases page:

• macOS (Intel): homo-macos-amd64
• macOS (Apple Silicon): homo-macos-arm64

Then make it executable and add to your PATH:

chmod +x homo-macos-arm64
sudo mv homo-macos-arm64 /usr/local/bin/homo

• Rust (latest stable, install here)
• macOS 11+ (Apple Silicon or Intel)

# Clone the repo
$ git clone https://github.com/CJHwong/homo.git
$ cd homo

# Build the app
$ cargo build --release

# Optionally, install to your Cargo bin directory
$ cargo install --path .

echo '# Hello, world!' | homo

Or stream a file:

tail -f README.md | homo

homo README.md

• src/main.rs — Entry point, handles GUI/streaming mode detection
• src/gui/ — Complete GUI implementation using AppKit bindings
  • delegate.rs — App delegate handling window lifecycle and content updates
  • view.rs — WebView wrapper for rendering HTML with Mermaid support
  • window.rs — Window creation and management
  • types.rs — Style preferences and theme management
• src/markdown/ — Markdown parsing with syntax highlighting
• src/streaming.rs — Intelligent streaming with boundary detection
• src/content.rs — DocumentContent struct for thread communication
• src/menu.rs — Menu system with preferences and actions
• src/plugins/ — Plugin system for extensible content processing
  • manager.rs — Plugin registration and execution management
  • mermaid.rs — Mermaid diagram rendering plugin
  • katex.rs — LaTeX/math rendering plugin
• src/error.rs — Custom error types and handling

cargo run

To test streaming mode:

echo '## Streaming test' | cargo run --

HOMO stores user preferences (font size, font family, theme) in macOS UserDefaults. These preferences persist across app launches.

View current preferences:

defaults read homo StylePreferences

Reset preferences to defaults:

defaults delete homo StylePreferences

• Font Family: System, Menlo, Monaco, Helvetica
• Font Size: Adjustable via keyboard shortcuts or menu
• Theme: Light, Dark, System (follows macOS appearance)

• ⌘ + = (or ⌘ + +): Increase font size
• ⌘ + -: Decrease font size
• ⌘ + 0: Reset font size to default

• ⌘ + 1: System font
• ⌘ + 2: Menlo font
• ⌘ + 3: Monaco font
• ⌘ + 4: Helvetica font

• ⌘ + L: Light theme
• ⌘ + D: Dark theme
• ⌘ + S: System theme (follows macOS appearance)

• ⌘ + T: Toggle mode (for displaying the raw Markdown)

• ⌘ + C: Copy selected text
• ⌘ + A: Select all text
• ⌘ + W: Close window

MIT