Hi Product Hunt 👋 I'm Hyunbin, an indie developer from Korea. I built Rune because every Markdown editor I used made me choose between two columns — raw source on the left, a rendered preview on the right. That split always pulled my eyes away from where I was actually writing. I wanted one pane: text that just becomes formatted as I type, with the raw markdown showing only on the line my cursor is on. Getting that to feel right was the hard part. Everything lives in a single CodeMirror 6 document — code blocks, Mermaid diagrams, KaTeX math, and tables render in place, and collapse back to source as the cursor enters the line. I built it on Rust + Tauri so it opens instantly and stays small instead of bundling a whole browser. And since I'm based in Korea, Korean/CJK typography is first-class, not an afterthought. It's early (v0.1.3) and it's just me — so I'd genuinely love your feedback on what feels good, what's missing, and what breaks. Free and open source (MIT), for macOS, Windows, and Linux. Repo: https://github.com/JangHyun-bin/... Thanks for taking a look 🙏

Rune

Markdown that renders as you type — code, diagrams, math

Markdown that renders as you type — code, diagrams, math