md-editor

A Markdown editor where you write on the rendered text and save clean Markdown. TeX formulas, aligned tables, highlighted code, document templates, and export to PDF/DOCX/ODT/LaTeX — lightweight, portable (Qt6/C++17, zero external dependencies), in 9 languages.

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Downloads

System	File	Notes
Linux (x86_64)	md-editor-2.8.4-x86_64.AppImage	Single-file executable. chmod +x and double-click.
Windows (x64)	md-editor-2.8.4-windows-x64.zip	Portable: unzip and run md-editor.exe.
macOS (Apple Silicon + Intel)	md-editor-2.8.4-macos-universal.dmg	First launch: Ctrl-click → Open (binary not signed).

All downloads, including previous versions, on the releases page.

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Installing on Linux

The AppImage is a single self-contained executable — no installation, no root:

1. chmod +x md-editor-*-x86_64.AppImage
2. Run it (double-click, or ./md-editor-*-x86_64.AppImage document.md).

If it does not start:

• dlopen(): error loading libfuse.so.2 — AppImages mount themselves with FUSE 2, which recent distributions no longer install by default. Either install it (sudo apt install libfuse2 on Debian/Ubuntu, sudo dnf install fuse-libs on Fedora) or skip the mount altogether: ./md-editor-*-x86_64.AppImage --appimage-extract-and-run.
• Could not load the Qt platform plugin "xcb" — a minimal or container-based system is missing the X libraries Qt needs: sudo apt install libxcb-cursor0 libxkbcommon-x11-0 libfontconfig1. Adding QT_DEBUG_PLUGINS=1 to the command prints which library is missing.
• Nothing happens on double-click — the execute bit (step 1) is missing. Some file managers stay silent about it; run it from a terminal to see the error.
• The AppImage does not add itself to the applications menu. If you want an entry, either use AppImageLauncher or install from source (sudo ./install.sh), which does register it.

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Installing on Windows

The Windows build is portable: unzip and run md-editor.exe — no installer. The binary is not signed yet, so SmartScreen may show a blue "Windows protected your PC" screen on first run. To proceed, click More info → Run anyway. This only happens until the build earns SmartScreen reputation (or gets code-signed).

If it does not start:

• VCRUNTIME140.dll was not found (or MSVCP140.dll) — the app is built with Microsoft's compiler and needs its runtime, which most machines already have. Install the Visual C++ Redistributable (x64).
• The app starts and closes immediately, or complains about a missing DLL — make sure you extracted the whole ZIP, not just md-editor.exe. The Qt DLLs and the platforms\ folder next to it are part of the program.
• Windows keeps warning about every file — right-click the downloaded ZIP → Properties → Unblock, and extract it again. Windows marks files that come from the internet, and the mark survives extraction.

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Installing on macOS

The macOS build is not signed or notarized (Apple code signing requires a paid Developer account). Gatekeeper will therefore block it on first launch with a "cannot be opened because it is from an unidentified developer" message. This is expected and the app is safe — to open it the first time:

1. Open the .dmg and drag md-editor into Applications.
2. In Applications, Ctrl-click (or right-click) the app and choose Open.
3. Confirm Open in the dialog that appears.

You only need to do this once; afterwards it launches normally with a double-click. Alternatively, after the blocked attempt, go to System Settings → Privacy & Security and click Open anyway.

If it does not start:

• "md-editor is damaged and can't be opened. You should move it to the Trash" — the download is not corrupt: this is the quarantine flag macOS puts on unsigned downloads. Remove it and open normally: xattr -dr com.apple.quarantine /Applications/md-editor.app.
• Ctrl-click → Open does not offer an "Open" button — on macOS 15 (Sequoia) and later that shortcut is gone for unsigned apps. Launch it once (it will be blocked), then go to System Settings → Privacy & Security, scroll down and click Open Anyway.

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What it does

• True WYSIWYG: you never see the Markdown syntax, you see the rendered output.
• Multiple documents in tabs: open several files at once, each in its own tab; the open tabs reopen on the next launch.
• Clean round-trip: what you open is what you save. Aligned tables, quotes, nested lists, task lists, footnotes, code blocks with syntax highlighting, ==highlight== and ^super^ / ~sub~ script.
• Type Markdown and it formats itself: # , > , - , 1. at the start of a line become the heading, quote or list in place, marker included.
• TeX formulas $…$ and $$…$$ with real super- and subscripts and a live preview — no external dependencies. Double-click to edit.
• Diagrams: mermaid and plantuml code blocks are previewed as an image below the block (needs the external mmdc / plantuml tool; degrades gracefully with an install hint if it is missing).
• Admonitions / callouts (> [!NOTE], [!TIP], [!IMPORTANT], [!WARNING], [!CAUTION]) shown as coloured boxes, round-trip compatible with GitHub.
• Tables without the syntax: a floating bar appears over the table to add or remove rows and columns and set the column alignment; Tab walks the cells and adds a row at the end; rows can be sorted by a column.
• Code blocks: hovering shows the language (click to change it) and a button that copies the block.
• Spell checking (Hunspell): misspellings underlined in the document's language, with suggestions and a personal dictionary.
• Document templates (File → New from template) and reusable snippets (Insert → Snippet) for content you write often.
• Export to PDF, HTML, ODF (.odt), LaTeX (.tex), DOCX (.docx), EPUB (.epub) and plain text (.txt), preserving the document language and the formula formatting; the PDF embeds the title and author from the front matter.
• Import from HTML, EPUB and more (File → Import): converts a web page or an EPUB book to Markdown natively, and DOCX/ODT/RTF/LaTeX/reStructuredText… via Pandoc (if installed); opens the result as a new untitled document.
• YAML / TOML front matter preserved verbatim on save.
• Navigable outline panel (F9), find and replace (Ctrl+F / Ctrl+H), autosave and crash recovery.
• Distraction-free mode (F11) and focus mode (typewriter scrolling + dimming), full-interface zoom (Ctrl+wheel), 8 light and dark themes (including GitHub, Monokai, Solarized and a true high-contrast one) plus an automatic warm night light, Markdown source view and side-by-side split view.
• 9 languages: Spanish, English, German, French, Italian, Portuguese, Polish, Dutch and Romanian.
• Paste images from the clipboard straight to disk as ![](path), instead of embedding them — so the Markdown stays portable.
• External file watching: if the file changes on disk, the app detects it and offers to reload.
• Accessibility: accessible names on the editor, panels and controls; status messages announced to screen readers; full keyboard operation; a true high-contrast theme and whole-interface zoom for low vision.

Common shortcuts

Shortcut	Action
Ctrl+N / Ctrl+O / Ctrl+S	New / Open / Save
Ctrl+Shift+S / Ctrl+P	Save as… / Print
Ctrl+W / Ctrl+Shift+R	Close tab / reopen the last closed one
Ctrl+B / Ctrl+I / Ctrl+U	Bold / Italic / Underline
Ctrl+E / Ctrl+K	Inline code / link
Ctrl+1…Ctrl+6	Heading levels 1 to 6
Ctrl+Shift+U / Ctrl+Shift+O / Ctrl+Shift+T	Bullet / numbered / task list
Ctrl+Shift+F	Insert formula
Ctrl+F / Ctrl+H / F3	Find / replace / find next
Ctrl+G / Ctrl+L	Go to heading / line
Ctrl++ / Ctrl+- / Ctrl+0	Zoom in / out / reset
Ctrl+Shift+M / Ctrl+Shift+D	Markdown source view / split view
Ctrl+Shift+P	Command palette (find & run any action)
Ctrl+,	Preferences
F11 / F12	Distraction-free mode / focus mode
F9 / F1	Outline / Help

Full list under Help → Manual inside the app.

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Building from source

Legal note: the code is free software under GPL-3.0. You may clone, build, modify and redistribute it, as long as derivatives stay under the GPL-3.0. See License.

Dependencies

• CMake ≥ 3.16
• Qt 6.5 or higher (modules Widgets, PrintSupport, LinguistTools, Test) plus its private headers: the ODF export uses Qt's private QZip. On Debian/Ubuntu these ship in a separate package from qt6-base-dev, and without them CMake fails at configure time with "Imported target Qt6::GuiPrivate includes non-existent path".
• A C++17 compiler (GCC 9+, Clang 10+, MSVC 19.20+)
• Optional: Hunspell, for spell checking. Without it everything else builds and the spell checker is simply inactive. On Linux the dictionaries are the system ones (hunspell-en-us, hunspell-es…).

# Debian / Ubuntu
sudo apt-get install cmake g++ qt6-base-dev qt6-base-private-dev libhunspell-dev

Linux / macOS

cmake -S . -B build
cmake --build build
./build/md-editor [file.md]

Shortcut: ./build.sh -x example.md configures, builds and runs.

Windows (PowerShell)

cmake -S . -B build -G "Visual Studio 17 2022"
cmake --build build --config Release
build\Release\md-editor.exe

Tests

ctest --test-dir build --output-on-failure

Tests use Qt Test. CMake picks the platform plugin per system: headless (offscreen) on Linux and macOS, native on Windows — where offscreen has no font database, which breaks Markdown serialisation and silences the test output.

Installation (Linux, optional)

sudo ./install.sh                     # → /usr/local
PREFIX="$HOME/.local" ./install.sh    # → ~/.local (no sudo)

Installs the binary, the .desktop launcher and hicolor icons (PNG + SVG).

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License

This software is free software, distributed under the GNU General Public License v3.0 (GPL-3.0).

Copyright © 2026 Manuel Arias Calleja.

In short:

• ✅ You may use, study, and run the program for any purpose.
• ✅ You may redistribute copies, source or binary.
• ✅ You may modify it and distribute your modified versions — provided they are also released under the GPL-3.0 (same freedoms for everyone).
• ❌ You may not distribute a closed-source or proprietary derivative.

This is a strong copyleft licence: any fork must stay free and open under the same terms. Full text in LICENSE.

Contributions

This project does not accept pull requests. Development is by the author only. If you find a bug or have a suggestion, open an issue and the author will consider it. (The licence lets you fork and modify your own copy; that is independent of this repository's contribution policy.)

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Author

Manuel Arias Calleja — manuelariascalleja@gmail.com

If you find it useful, please ⭐ the repository — that is the simplest way to let me know it is helping someone.