Markdown Library ML-42 is a native macOS app for reading and editing markdown files already on disk, across as many folders and projects as you want, for $12.99 once.
Obsidian is a free, cross-platform note-taking app that stores notes as markdown files inside a vault, extendable with thousands of community plugins.
| Question | ML-42 | Obsidian |
|---|---|---|
| Interface | A sidebar of your folders, the document, and an inspector with the table of contents and a summary, ready on launch | Configurable panes, plugins and themes, assembled to fit |
| Storage model | Plain .md files in your existing folders; nothing added | Plain .md files too, organized into vaults. Each vault gets a .obsidian config folder written into it |
| Works on folders you already have | Yes. Point it at any folder, including an existing Obsidian vault; no import, no designation | Yes, through "Open folder as vault", which adopts the folder and writes config into it |
| Multi-project | Many folders open side by side, one search across all of them | One vault per window; no built-in cross-vault search |
| File ownership | Yours; the app adds nothing to the folder | Yours too. Obsidian's own claim is open file formats and "never locked in", and that claim holds |
| Native or Electron | Native SwiftUI and AppKit, with an NSTextView editor and Apple Intelligence integration | Electron-based and cross-platform, widely regarded as a well-optimized Electron app |
| Extensibility | None, by design: no plugins | Thousands of community plugins, themes, and an API |
| Graph view and backlinks | None | Graph view, backlinks, and a canvas ecosystem |
| Platforms | macOS 26 or later, Mac only | Windows, macOS, Linux, iOS, Android |
| Sync | None built in. Use whatever already syncs your folders: git, iCloud Drive, Dropbox | Optional paid Sync at $4 to $5 per user per month, or free through your own methods |
| Price | $12.99 once (introductory; it will rise) | Core app free, without limits |
| AI-agent workflow | Built for it. File watching reloads a file when an agent edits it; on-device summaries; search skips build and dependency folders | Files are agent-editable too, though that is not the app's framing; some plugins add AI features |
| Accounts and telemetry | None. It goes online only for web images in your documents and for feedback you choose to send | No account required for the core app; Sync and Publish, its optional paid services, do require one |
| Learning curve | Small, by design: open a folder, read, edit | Larger, because the power comes with configuration |
What you see when you open each app
Open ML-42 and it behaves like a native Mac window. You are reading the folder you pointed it at straight away, with no vault to create and nothing to configure before the first file renders as formatted markdown. The window has a sidebar of folders and files, the document, and an inspector, and FSEvents watches for changes made anywhere else.
Obsidian's first launch asks you to create or open a vault, and most of its power then arrives through community plugins, themes and settings you choose and install yourself. Assembling that setup is worth it for a lot of people. It is a different starting point from opening a folder and reading.
Obsidian stores plain markdown too, so what is different
This is the fair objection, and it is true: Obsidian stores notes as plain markdown files, and its own marketing says you are "never locked in." ML-42 does not dispute that.
The difference is what has to happen to the folder before you can read a file in it. Obsidian designates a folder as a vault, through "Open folder as vault," and writes its own .obsidian configuration folder into it. ML-42 opens any folder, including an existing Obsidian vault, without adopting it or writing anything into it. You can point ML-42 at a git repo, a docs directory or a vault, read and edit across all of them at once, and nothing changes about how those folders are organized.
Extensibility is where Obsidian wins
Obsidian has thousands of community plugins, themes, a graph view, backlinks and a canvas ecosystem. ML-42 has none of that, by design: no plugin system, no graph view, no extensibility API. If you want a customizable knowledge-management system, Obsidian is built for it and ML-42 is not trying to be.
Built around files an agent might be editing
ML-42 watches the files it is showing you with FSEvents and reloads automatically when an AI agent or another editor changes one on disk, so nothing on screen goes stale and there is nothing to refresh. Its command palette search also skips build and dependency folders, which matters when the folder is a code repo. Obsidian's files are just as editable by an agent, but reload behavior and agent work are not part of its framing; community plugins fill that gap if you install one.
ML-42 is a reader and editor for folders that exist for other reasons: repos, docs directories, agent context. If you are choosing a home for personal notes, Obsidian may simply be the better fit. ML-42 competes when the files already exist and need to stay where they are.
- You want plugins, themes and a customizable system: thousands of community plugins, a graph view and canvas. ML-42 deliberately has none of that.
- You need Windows, Linux, Android or iOS. ML-42 is Mac only, by design.
- You want a free tool. Obsidian's core app is free without limits, and it also stores plain markdown you own.
- Your files already live somewhere for other reasons, such as a git repo or a docs directory, and you do not want to turn that folder into a vault just to read one file.
- You work across many folders at once and want one search over all of them, without opening a separate vault for each.
- You use AI agents that edit files on disk and want the app to notice and reload automatically.
Also compare: Typora, iA Writer and Bear. All four side by side are on the home page.
Markdown Library ML-42
A native Mac reader and editor for the markdown in your repos and docs folders. No import, no vault.
Download on theMac App Store$12.99 once. Introductory price. It goes up later.