Reading and editing
View mode
In Markdown Library ML-42, every document opens in view mode: rendered and read-only. Headings, bold, links, lists, blockquotes, images, tables and code are all styled for reading, and scrolling stays smooth on long documents.
Edit mode
Switch to edit mode with the toolbar’s Edit button or View › Switch to Edit (Cmd+Shift+E) to see and change the raw markdown. Edit mode shows line numbers and behaves like a native text editor: every keystroke is immediate, with no rendering layer in the way. The same shortcut switches back to view mode. Line numbers can be turned off in Settings.
On-device summaries
With Apple Intelligence, each document gets a short summary written on your Mac. Nothing leaves your machine. The summary appears in the inspector next to the table of contents, and on the document cards in folder overviews.
Syntax highlighting
Fenced code blocks are highlighted for Swift, Python, JavaScript, TypeScript, Go, Rust, Java, Kotlin, C and C++, HTML, CSS, JSON, YAML, Shell, SQL and Ruby. Colours follow light and dark mode.
Tables
Markdown tables render in view mode as aligned grids with bold headers and row separators, and adapt to the window width. To change the pipe-delimited source, switch to edit mode.
Front matter
YAML front matter at the top of a document renders as a list of properties, keys and values, instead of raw text at the top of the page.
Floating toolbar
In edit mode, select text and a formatting toolbar appears: bold, italic, strikethrough, inline code, headings (H1 to H3), bullet list, numbered list, blockquote and link.
Keyboard shortcuts in edit mode
- Cmd+B: bold
- Cmd+I: italic
Find in a document
- Cmd+F: find, with a match count
- Cmd+G: find next
- Cmd+Shift+G: find previous
- Cmd+E: use the selection for find
- Cmd+J: jump to the selection
Auto-save
Edits are written back to disk automatically after a short pause. There is nothing to save by hand.
File watching
When another tool changes a file on disk, such as an AI agent or another editor, ML-42 notices through FSEvents and reloads the file.
Navigation
Command palette
Cmd+K (File › Quick Open) opens a search across all your projects. Results appear by filename as you type and by content right after. Each result shows its type (project, folder or document) and its path. Use the arrow keys to move and Return to open.
Back and forward
Navigation history works like a browser, across files and folders. Cmd+[ goes back and Cmd+] goes forward. Both are also toolbar buttons.
Table of contents
The inspector lists the current document’s headings. Click one to scroll there. Show or hide the inspector with Cmd+Option+I.
Breadcrumbs
Every document and folder view shows a breadcrumb path in its header. Click a segment to move up the hierarchy.
Inline rename
Click the title in a document or folder header to rename it in place. Press Return to confirm or Escape to cancel. Files and folders can also be renamed from the sidebar’s context menu.
Organisation
Projects
Add any folder as a project with File › Add Project (Cmd+Shift+O). ML-42 remembers your projects between sessions with security-scoped bookmarks. Each project appears in the sidebar with its folder hierarchy, filtered to show only markdown files. File › Reload Project (Cmd+R) rereads a project from disk.
Sidebar
The sidebar keeps one project expanded at a time. As you move into subfolders, the tree expands to follow. Folders show how many documents they hold.
Favorites
Star any file or folder from the toolbar. Starred items appear in the Favorites section at the top of the sidebar.
Folder overview
Click a folder to see an overview: document cards with summaries and modification dates, subfolders with document counts, and breadcrumb navigation.
New files and folders
Cmd+N creates a new document and Cmd+Shift+N a new folder, in the folder you are looking at, or next to the file you have open.
Integration
Show in Finder
Reveal the current file or folder in Finder from the toolbar or the File menu. Every document is a real file on disk; ML-42 does not copy or import anything.
Copy and share
The toolbar copies the current document’s raw markdown, and the standard macOS share sheet sends the file through any system extension.
Appearance and settings
Light and dark mode
Switch between light and dark from the sidebar, or choose System, Light or Dark in Settings. The document, the code highlighting and the rest of the window follow.
Text size
Cmd+= and Cmd+- make the text larger and smaller. Both are also toolbar buttons.
Settings
Settings has three tabs.
- Browsing: appearance (System, Light or Dark); the three sidebar settings (hide folders without markdown files, hide hidden files and folders, ignore build and dependency folders), which apply the next time you open or reload a project; and the language for summaries.
- Reading: three presets (Reading, System and Sans), then the body font (System, New York, Charter, Georgia, Helvetica Neue or Palatino), body size from 12 to 24 pt, line height, the mono font and its size from 10 to 22 pt, and the maximum content width from 500 to 1200.
- Editing: the edit-mode font, size and line height, and whether to show line numbers.
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.