Edmund

Edmund is a minimal, file-based, native Markdown editor for macOS with inline live preview.

https://github.com/user-attachments/assets/5c9097c7-68d2-4423-b0f5-495979775f6d

Whether as a companion alongside your Markdown knowledge base or as a standalone editor, Edmund blends in with macOS and works seamlessly with your files wherever they are.

Our goal is to be the CotEditor of Markdown editors, i.e. elegant, powerful, configurable, and native inside out.

⚠️ Edmund is currently in beta. See the roadmap for what's coming next :D

Differentiators

• Live preview: Typora/Obsidian-style WYSIWYG.
• File-based: Open .md files from anywhere. No vaults or dedicated folders required.
• Native: 100% Swift. Based on AppKit and TextKit 2. No Electron. Minimal dependencies.
• Fast: Handles ~1-2MB files with ease. No launch lag.
• Extensible: Opt-in math and Obsidian syntax. Extensions system coming soon!
• Private: Offline by default. Optional blocking of external links and HTML sanitization.

See my blog post for more of the motivation and design philosophy.

Screenshots

!Live preview in light and dark mode

!Inline and display math, and a Mermaid diagram

!Typing in a table cell, and a selected table column

!Find and Replace

!Toolbar, format bar, status bar and the inspector's outline

!Read mode

!The same document in Source mode and in live preview

!General, Edit and Themes settings

Installation

Get Edmund.dmg from the latest release, open it, and drag Edmund.app to Applications:

Alternatively, install with Homebrew:

brew install --cask i7t5/tap/edmund

[!WARNING]

If macOS reports that the app is 🚧DAMAGED🚧 when you're trying to open it for the first time, fear not.

The app is not damaged. It's just not signed properly because I am not a $99/yr-certified Apple Developer.

Good thing is there's an easy way to bypass the barrier.

To open Edmund (or any other "damaged" app) for the first time, choose one of the following:

- System Settings → Privacy & Security → scroll down → Open Anyway. Or,

- Run the following line in Terminal: xattr -dr com.apple.quarantine /Applications/Edmund.app

- You might also need to prepend the command with sudo.

Edmund checks for updates automatically; you can also browse version history here.

Dependencies

• swift-markdown
• SwiftMath
• Sparkle
• Lucide icons

Alternatives

If Edmund's not your thing, some of the following might be:

• Closed source

• Open source

The list is by no means exhaustive, and neither was it meant to be. I just wanted to give credit to the makers of these apps, esp. IMO the aesthetic open sourced ones. A comprehensive list may be found here.

Acknowledgements

• CotEditor for the philosophy
• Typora and Obsidian for much of the vision
• Swift Markdown Engine for the architecture reference
• Apple and Iowan Old Style for the aesthetics

• create-dmg, screenshot-studio, and shields for the utilities
• Claude, caveman, and ponytail for the engineering.
• RaTeX and beautiful-mermaid for extension functionalities

Most importantly, many thanks to our contributors:

License

Apache License 2.0