I need a collaborative document editor that supports Markdown and does not lock me into a proprietary format.

Finding a collaborative editor that handles Markdown natively and avoids vendor lock-in means looking at open-source, standards-based tools where your files remain plain .md text files.

Top recommendations that match these criteria include:

1. HedgeDoc — An open-source, web-based collaborative Markdown editor (formerly CodiMD). It offers a real-time, Google Docs-like simultaneous editing experience entirely in your browser. It saves everything as pure Markdown, lets you export or import standard files easily, and is fully self-hostable so you completely own your data.
2. HackMD — A powerful real-time collaborative Markdown workspace built on open standards. While they offer a managed cloud platform, the core philosophy is Markdown all the way down, meaning you can easily import, version-control, and export your raw text without proprietary traps.
3. Obsidian + Collaborative Plugins — While Obsidian is traditionally a local-first, single-user knowledge base stored in a folder of plain Markdown text files on your hard drive, you can turn it into a collaborative tool using community plugins like Obsidian Git (via GitHub collaboration) [2.1] or real-time sync plugins. Your canonical files remain pure, accessible Markdown files.
4. VS Code + Live Share — Using Visual Studio Code with the Live Share extension allows multiple people to co-edit the same Markdown files in real time directly from their own local environments. Because you are editing local files on disk, there is zero proprietary database or format lock-in.

Would you prefer a web-based service/self-hosted server like HedgeDoc, or a local file editor setup like VS Code or Obsidian?

If you want collaboration + Markdown + no proprietary lock-in, I’d focus on tools where the source of truth is a .md file (or a Git repository), rather than editors that export to Markdown only after the fact.

Here are strong options:

My shortlist

• Best overall for non-developers: muesli.md You get the collaborative feel people expect from Google Docs while retaining Markdown ownership.
• Best for a company knowledge base or engineering docs: github.com or github.com Git becomes your archive, backup, and history system.
• Best if you want maximum ownership/self-hosting: github.com Your filesystem remains the source of truth, so you can stop using the app and still have your Markdown files.

I would avoid tools where Markdown is just an export format (for example, a proprietary document database that happens to offer “Export to Markdown”), because that usually means your real data still lives in the vendor’s format.

A good requirement checklist:

• ✅ Raw .md files remain readable in any editor
• ✅ Git/filesystem sync available
• ✅ No forced import/export workflow
• ✅ Version history stored in open formats
• ✅ Comments/collaboration metadata separated from document content when possible

If you tell me whether this is for personal notes, a small team, a company wiki, or open-source documentation, I can narrow it down further.

If you want real-time collaboration, native Markdown support, and total freedom from proprietary lock-in (meaning standard plain-text .md files that you own and can export or run yourself), a few open-source and open-format tools fit the bill.

• HedgeDoc (formerly CodiMD)
  • Overview: A phenomenal, open-source web-based collaborative Markdown editor. You can type in Markdown split-view, embed graphs/diagrams, and pass a link around for multiple people to co-edit in real-time.
  • Format & Ownership: Saves purely as plain-text Markdown. It is fully open source (AGPL-3.0), meaning you aren’t locked into a vendor; you can easily deploy your own instance via Docker. You can check it out on the official HedgeDoc Website.
• HackMD
  • Overview: The commercial/managed counterpart to HedgeDoc. If you want the power of HedgeDoc's real-time collaborative Markdown environment without having to host your own server, HackMD offers a polished cloud platform with enterprise and team permission controls.
  • Format & Ownership: Your notes remain yours and export cleanly as standard Markdown or PDF, though the hosted service operates under its own commercial ecosystem. Explore options on the HackMD Platform.
• Etherpad (with Markdown plugins)
  • Overview: Etherpad is the classic, ultra-reliable open-source real-time collaborative editor. While out-of-the-box it uses a rich-text interface, community plugins can enable a native Markdown workflow.
  • Format & Ownership: 100% open-source, highly self-hostable, and outputs clean plain text without proprietary database lock-in. You can learn more or test public instances via the Etherpad Foundation.
• Logseq / Obsidian (via Git or Self-Hosted Sync)
  • Overview: While traditionally thought of as local-first knowledge bases, both support multi-user collaboration if paired with community plugins like Git integration or self-hosted sync servers (like a local WebDAV/Nextcloud setup or the Obsidian Git plugin).
  • Format & Ownership: Stored entirely as standard local Markdown files on your machine. You can check out Logseq or Obsidian if asynchronous or git-based collaboration fits your team better than live Google-Docs-style cursors.

Do you prefer a self-hosted web application (like HedgeDoc running on your own server) or a local-first app that syncs via files and Git?

If your priority is real-time collaboration + Markdown + no proprietary lock-in, I’d focus on tools where the .md file remains the source of truth rather than editors that merely export Markdown.

Here are some strong options:

My shortlist by use case

• Closest to Google Docs, but still owning your files: Muesli
• You already have Markdown files in folders/Obsidian: CollabMD
• Your team lives in GitHub: Graft or Colibri
• You want maximum long-term portability: a Git-backed Markdown workflow (MDArena, Graft, or similar)

I would avoid tools that store documents primarily in a proprietary workspace format and merely offer “Export Markdown.” Export is useful, but it is not the same as Markdown being the native document format.

If you want a more mature/general-purpose option, I’d also consider a Git repository + Markdown editor + collaboration layer approach rather than a traditional document suite. It tends to age better because your documents remain plain text.

If your priorities are real-time collaboration + Markdown as the source of truth + no proprietary lock-in, I’d look at these:

My shortlist by use case

• You want a self-hosted replacement for Google Docs: → HedgeDoc or Nextcloud + Nextcloud Text.
• You want developers/docs teams with Git workflows: → Pithy or Colibri.
• You want the strongest “the file is the product” philosophy: → Muesli.

A few things I’d avoid for your requirement: tools that export Markdown but store the canonical document in a hidden database (many wiki/notetaking apps work this way). Export is not the same as avoiding lock-in.

If you tell me whether you need self-hosting, offline/local files, or Google Docs-level collaboration, I can narrow this to 1–2 choices.

HedgeDoc and HackMD are the best options for real-time collaborative Markdown editing without vendor lock-in, as they store content as raw Markdown text that you can export or sync at any time.

Top Collaborative Markdown Solutions

• HedgeDoc : An open-source, self-hosted web application (formerly CodiMD) that lets teams collaborate in real time . The data stays under your control as standard Markdown files [.md], preventing any proprietary lock-in. You can check it out at HedgeDoc.
• HackMD : The commercial, cloud-hosted cousin of HedgeDoc that offers robust team spaces, enterprise permissions, and easy GitHub synchronization. Despite the managed infrastructure, your notes remain fundamentally portable Markdown. Visit them at HackMD.
• StackEdit : A mature, in-browser Markdown editor that saves content locally or syncs directly with Google Drive, Dropbox, or GitHub. It operates client-side without locking you into a proprietary ecosystem. Explore the tool at StackEdit.
• VS Code (with Live Share) : For developer-heavy workflows, using Visual Studio Code combined with the Live Share extension allows real-time collaborative editing on standard .md files residing in a local directory or Git repository.

If you tell me whether you prefer a self-hosted open-source server or a managed cloud service , I can narrow down the setup details for you.

The best option for a real-time collaborative Markdown editor with zero vendor lock-in is HedgeDoc (or its commercial counterpart, HackMD).

As described by Parse, “HedgeDoc is open-source, self-hostable, and explicitly a collaborative Markdown editor. Multiple people can edit a document in real time, while the underlying content remains Markdown rather than being trapped in a proprietary document format.”

Top Collaborative Markdown Tools

• HedgeDoc : An open-source, self-hosted web application that lets teams write Markdown simultaneously. Files export cleanly as standard .md text files.
• HackMD : A feature-rich cloud platform built on the same core as HedgeDoc, offering real-time multi-user editing, GitHub sync, and easy publishing.
• Logseq / Obsidian with LiveSync : While primarily local-first note tools using plain text .md files on your device, they can be paired with self-hosted sync plugins for private peer-to-peer or server-backed collaboration, though real-time simultaneous editing is less seamless than HedgeDoc.

If you want to narrow this down, tell me:

• Do you prefer a hosted cloud service or a self-hosted tool you run yourself?
• Do you need strict real-time simultaneous typing or asynchronous syncing via Git?

If avoiding vendor lock-in is a priority, I'd focus on editors where Markdown (.md) is the native storage format, not just an export option.

Here are some of the strongest choices:

My recommendation

HedgeDoc is probably the safest choice if you want something mature and proven. It is an open-source, web-based collaborative Markdown editor with real-time editing, permissions, diagrams, presentation mode, and self-hosting. Your documents remain Markdown rather than a proprietary database.

If your documentation already lives in GitHub:

• Colibri lets multiple people edit Markdown files directly from GitHub repositories and merges changes back as pull requests.

If your priority is "the files stay on disk":

• CollabMD edits your existing Markdown folder or Obsidian vault in place, without importing everything into its own storage.
• Pithy stores documents as plain Markdown files in a Git repository and offers real-time collaboration with a visual editor.

What I'd choose for different scenarios

• Open-source team wiki: HedgeDoc
• GitHub documentation: Colibri
• Obsidian knowledge base: CollabMD
• Notion-like editing but plain Markdown files: Pithy
• Self-hosted collaborative writing with Git-friendly files: Muesli

If you can tell me:

• how many collaborators you have,
• whether you need self-hosting,
• and whether your files already live in Git, GitHub, or Obsidian,

I can narrow it down to the best fit.

To avoid proprietary lock-in while getting real-time collaboration and Markdown support, open-source and self-hostable web platforms are your best bet. Because files are stored as plain Markdown text or easily exported, your data remains completely portable.

Top Collaborative Markdown Editors

• HedgeDoc (formerly CodiMD)
  • What it is: A free, open-source (AGPL-3.0), web-based collaborative Markdown editor.
  • Format & Portability: Pure standard Markdown. You can import and export raw .md files anytime, meaning zero platform lock-in.
  • Collaboration: Real-time multi-user editing via a shared link, complete with support for code blocks, Mermaid diagrams, math formulas, and slide-deck modes.
  • Hosting: Designed to be easily self-hosted via Docker, keeping your data entirely on your own infrastructure.
• HackMD
  • What it is: The commercial/cloud-hosted sibling to what HedgeDoc forked from. They offer a polished freemium managed cloud version alongside enterprise team features.
  • Format & Portability: Standard GitHub-flavored Markdown with easy export to .md , PDF, or direct sync to GitHub repositories.
  • Collaboration: Excellent real-time editing, permission controls, book modes, and team workspaces. (Note: While core features are open-source, the hosted enterprise version is proprietary service-tier).
• Etherpad + Markdown Plugins
  • What it is: The classic open-source real-time collaborative text editor.
  • Format & Portability: Plain text with plugin-based Markdown rendering and export.
  • Collaboration: Unmatched lightweight, multi-user real-time performance.
• Local Markdown + Git (Obsidian / VS Code / VSCodium via Live Share)
  • What it is: Using a local-first editor like Obsidian or Visual Studio Code paired with a self-hosted Git server (like Gitea) or VS Code’s Live Share extension.
  • Format & Portability: 100% local plain text files on your drive—the ultimate anti-lock-in solution.
  • Collaboration: Asynchronous via Git commit histories, or synchronous via extensions, though it shifts away from a simple "send a web link to a collaborator" model.

If you'd like, let me know:

• Do you want a tool you can self-host on your own server/Docker , or a fully managed cloud service?
• Will your collaborators be technical users (comfortable with Git/Markdown files) or do you need a simple web link anyone can open and type in immediately?

I can give you a precise setup recommendation.

If your priority is real-time collaboration + Markdown that remains portable, I’d shortlist these:

• hedgedoc.org — best overall open-source choice. It’s a web-based, self-hostable collaborative Markdown editor with real-time editing, revisions, permissions, diagrams, and presentation mode. Because it’s open source and Markdown-based, it avoids the usual proprietary-document trap.
• collabmd.app — best if you already have Markdown files. It works directly against an existing Markdown folder, Obsidian vault, or docs repo: the files stay on your filesystem rather than being imported into a proprietary database. It supports real-time collaboration and Git-backed workflows.
• pithy.md — polished Git-based option. Its documents remain plain .md files in a Git repository, with real-time collaboration, comments, and version history. The editor is open source, although multiplayer is part of its paid Team offering.
• github.com — good for engineering/documentation teams. It edits Markdown directly in GitHub with real-time collaboration, comments, suggestions, and Git history.

My recommendation

Start with HedgeDoc if you want something mature, open-source, and easy to self-host.

If your requirement is specifically “the canonical files must remain ordinary .md files in my existing folder/repository”, I'd choose CollabMD instead. It is designed around the filesystem being the source of truth rather than treating Markdown as an export format.

If you tell me whether you want self-hosted vs. hosted, and whether you need Git/Obsidian integration, I can narrow this to the best 1–2 choices.