Hi HN,

I built a macOS-native Markdown viewer/editor called Markdown Prism.

GitHub: https://github.com/hulryung/markdown-prism

I originally built this for myself. I wanted a lightweight Markdown viewer on macOS that:

wasn’t Electron-based

rendered GFM properly

supported LaTeX math and Mermaid diagrams

worked fully offline

Most native apps I tried were either minimal but missing key features (math, diagrams), or full-featured but Electron apps. I wanted something in between — native feel, but with the mature JS Markdown ecosystem.

How it works

It’s a hybrid approach:

SwiftUI for the native app shell

WKWebView for rendering

markdown-it, KaTeX, highlight.js, and Mermaid.js bundled locally

So you get native performance and integration (Quick Look, file watching, drag-and-drop), but still benefit from battle-tested JS rendering libraries. Everything is bundled for offline use.

Features

Split-pane editor with live preview (400ms debounce)

GFM (tables, task lists, strikethrough)

LaTeX math via KaTeX

Mermaid diagram support

Syntax highlighting (190+ languages)

Quick Look extension (preview .md in Finder)

Dark mode

File watching for external edits

Install via:

brew install hulryung/tap/markdown-prism

or download the DMG from the website.

It’s free and open source (MIT), macOS 14+.

Would love feedback — especially from people who use Markdown heavily. What’s missing? What would make this your daily Markdown tool?

Show HN: Markdown Prism – A Non-Electron Markdown Editor for macOS