Show HN: A wysiwyg Markdown editor for macOS that works with agents

Category: devtools

Tags: markdown, macos, wysiwyg, crdt, collaborative-editing

Score: 7.3/10 (Innovation: 7, Technical: 8, Documentation: 8, Utility: 6)

editmd is a native macOS WYSIWYG Markdown editor that renders Markdown in place while saving back as plain Markdown. It stands out for merging concurrent external edits (e.g., from coding agents) using Yjs CRDTs, with careful file-watching, encoding preservation, and a strict no-network policy for the WKWebView. The architecture cleanly separates pure merge/persistence logic from UI with property tests.

Target audience: developers and technical writers on macOS

Repository: https://kirahowe.com/2026/oct/22/editmd-0-1-0 · TypeScript · MIT

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