What changed in the format

• Tools that create an .mdz now always write a manifest.json that names the spec version and the main document. Apps that open one still don't require it.
• An archive can carry an AGENTS.md at its root: instructions that tell AI agents how to handle the archive safely.
• Paths inside an archive are case-sensitive, so Images/Logo.png and images/logo.png are different files.
• Links can point to files next to an archive and into other archives, in apps that support it, within a trust boundary. Wikilinks and other link styles are allowed.
• Apps that save an archive must keep the manifest fields and files they don't know about.

Read the specification, or the full list of changes.

MDZip Studio 1.6

• On WinGet: winget install MDZip.Studio.
• A portable version: one .exe that runs without installing.
• Large documents show their images within seconds, even with thousands of them.
• Color scheme and page width menus, remembered between sessions.
• Copy and Copy All as plain text, formatted text, HTML or Markdown.
• View → Load Remote Images turns https: images off for anyone who doesn't want documents contacting other servers.

Release notes · MDZip Studio

VS Code extension 1.5

• Remote images now show, as in VS Code's own Markdown preview, with the mdzip.remoteImages setting to turn them off.
• Page width, Copy and Copy All menus, as in Studio.
• The color scheme follows your VS Code theme, and Light or Dark can override it.

Release notes · VS Code extension

The mdz CLI and the libraries

• mdz 2.0 is on WinGet: winget install MDZip.Cli.
• @mdzip/core-js 2.0.1 and MDZip.Core 2.0.1 implement spec 1.2.0 for JavaScript and .NET.
• @mdzip/editor 2.2.0 adds footnotes, task list checkboxes and Mermaid 12 diagrams to every app built on it.

See Tools for downloads.

I'm sharing the first draft of a new open file format spec: MDZip (.mdz).

The problem it solves: Markdown is great for writing, but sharing a document with images and multiple files means sending a folder, a repo link, zip or a tarball — none of which are friendly to non-technical recipients. .mdz is simply a standard ZIP archive with a (loosly) defined structure — Markdown content, assets, and optional metadata bundled into one portable file. Rename it to .zip and extract, and it works with any existing tool, no special software needed. With appropriate ecosystem support, it becomes useful without renaming/unzipping/zipping.

What's here now:

• A full draft spec (v1.0.0-draft) — format structure, manifest schema, conformance requirements, implementation guidance, AI agent prompting tips
• A companion site at MDZip.org with use cases, a future projects wishlist, and developer resources

What I'm looking for:

• Feedback on the spec itself — anything unclear, missing, or wrong
• Interest in building tools — VS Code extension, Obsidian plugin, CLI, Pandoc reader/writer, native OS preview handlers, and more are all on the wishlist
• Real-world use cases I haven't thought of

The spec is CC BY 4.0. Everything is open. If you build something, please share it here.