OMD — Edit documents, not markup

OMD is a VS Code WYSIWYG editor for .md files that lets you visually edit markdown elements — callouts, tables, task lists, code, diagrams, charts, comments — while the file on disk stays plain, GitHub-renderable markdown.

The round-trip is the point: open a file, save it without editing, and it comes back byte-for-byte. OMD is a rich view over your markdown, never a separate format converted at save — so nothing about your file is proprietary, and it renders the same on GitHub as it does here.

• Rich rendering of plain GFM — GitHub alert callouts, task-list checkboxes, syntax-highlighted code, Mermaid diagrams, and KaTeX math, all edited inline.
• Smart blocks — insert with /: callouts, collapsible sections, tabs, columns, an interactive chart (backed by a real data table), YouTube embeds, image galleries, a live table of contents, dates, footnotes, and link cards (rich URL previews). Each serializes to a form a plain markdown reader still understands.
• Spreadsheet-style tables — overlay controls, move/sort columns and rows, keyboard navigation, and high-fidelity copy/paste to and from Excel, Sheets, and Word.
• Comments & collaboration — thread a comment on any selection; comments live in the file and survive every round-trip.
• References & backlinks — [[wikilinks]], @mentions, and #issues render as real links; backlinks across the workspace show in the sidebar.
• Export — one-click self-contained HTML (print to PDF from there).
• Wiki-aware — edits a cloned GitHub Wiki's flat page set correctly, including the space↔dash page-name mapping.

1. Download the .vsix from the latest release and install it with code --install-extension omd-<version>.vsix.
2. Open a .md file and run OMD: Open in OMD editor. Installing OMD does not change which editor opens markdown, so this is how you see it — try it on a file you know.
3. Press / in the document for the block menu, or use the toolbar.
4. Like it? Run OMD: Make OMD the default Markdown editor and .md files open in OMD from then on. OMD: Restore the built-in Markdown editor undoes that at any time, and OMD: Reopen as plain text drops a single file back to plain text without changing the default.

New to it? Open the bundled showcase/ wiki in the source repo — it exercises every feature.

OMD works fully offline. It makes a network request only when you ask it to:

• Link cards fetch a page's preview metadata (title/description/image) — only when you insert or refresh a card, never automatically on load. The fetched values are cached in your file so the card renders offline afterward.
• GitHub integration (contributors for @mentions, issues for #references) uses VS Code's built-in GitHub sign-in and is opt-in via OMD: Connect GitHub; on open it only uses an existing session and never prompts.

OMD collects no telemetry.

All documentation lives under docs/ — start at docs/README.md for the map. In short: the design corpus (why OMD is shaped the way it is) is in docs/design/; build/test/round-trip notes are in CONTRIBUTING.md; release and operational runbooks are in docs/operations/.

Please file issues in the repo.

OMD was developed almost entirely using Claude Code.  The repo contains agent-oriented documents to help guide Claude. As the maintainer of OMD, I understand that the use of AI to build software offends some.  There are likely other ways to edit markdown files that are more aligned to those worldviews.

MIT. Bundled third-party code is listed in THIRD-PARTY-NOTICES.md.