KMDView

A lightweight, KDE-native application for previewing Markdown files on Linux.

KMDView renders .md, .mkd, and .markdown documents with readable typography, adjustable column width, and multiple reading themes. It integrates with KDE Plasma through standard reverse-DNS packaging, a desktop entry, AppStream metadata, and a hicolor icon.

Features

• Native markdown preview using Qt's built-in renderer
• Relative image and link resolution for local documents
• Readable typography with clear heading hierarchy, code blocks, blockquotes, and tables
• Adjustable content width via toolbar slider (480 px up to full window width)
• Full-height document panel with internal scrolling for long files
• Six reading themes: Light, Dark, Sepia, Solarized Light, Solarized Dark, High Contrast
• Persistent settings for theme, width, and full-width mode
• Multiple ways to open files: command line, File menu, drag-and-drop, Dolphin "Open With"
• Reload without restarting the application
• KDE Plasma integration: taskbar icon, MIME associations, Office category in the app launcher

Screenshots

Open a markdown file and use View → Theme to switch reading themes. Adjust Width in the toolbar to change the document column size.

Requirements

Build tools

Dependency	Minimum version
CMake	3.20
Extra CMake Modules (ECM)	6.0
Qt 6	6.6 (Core, Gui, Widgets)
C++ compiler	C++17

Debian / Ubuntu

sudo apt install \
  cmake \
  extra-cmake-modules \
  qt6-base-dev \
  build-essential

Fedora

sudo dnf install \
  cmake \
  extra-cmake-modules \
  qt6-qtbase-devel \
  gcc-c++

Optional: KDE Frameworks

KMDView works with Qt 6 and ECM alone. For deeper KDE Frameworks integration (KAboutData, Ki18n), you can additionally install:

sudo apt install libkf5coreaddons-dev libkf5i18n-dev libkf5xmlgui-dev

Building from source

Clone the repository:

git clone https://github.com/BusyBeaverSoftware/KMDView.git
cd KMDView

Configure, build, and install to ~/.local (recommended for user installs):

cmake -B build -DCMAKE_INSTALL_PREFIX="$HOME/.local"
cmake --build build --parallel
cmake --install build

Ensure ~/.local/bin is on your PATH:

export PATH="$HOME/.local/bin:$PATH"

System-wide install

cmake -B build -DCMAKE_INSTALL_PREFIX=/usr
cmake --build build --parallel
sudo cmake --install build
sudo update-desktop-database /usr/share/applications

Uninstall

If you used the default ECM uninstall target:

cmake --build build --target uninstall

Usage

# Open a specific file
kmdview README.md

# Open an empty window
kmdview

Inside the application:

• File → Open to browse for a markdown file
• File → Reload (or press F5) to refresh the current document
• View → Theme to switch reading themes
• Width slider in the toolbar to adjust the document column (drag fully right for 100% width)
• Drag and drop .md files onto the window

After installation, Dolphin and other file managers can open markdown files with KMDView via Open With.

KDE integration

KMDView follows KDE application conventions:

Item	Value
Application ID	org.kde.kmdview
Binary	kmdview
Desktop file	org.kde.kmdview.desktop
AppStream ID	org.kde.kmdview
Icon name	org.kde.kmdview
Launcher category	Office
MIME types	text/markdown, text/x-markdown

After installing or updating the desktop file locally:

update-desktop-database ~/.local/share/applications

If the launcher does not update immediately, log out and back in or restart Plasma.

Project layout

KMDView/
├── CMakeLists.txt              # Root build and install rules
├── org.kde.kmdview.desktop     # Desktop entry for Plasma / XDG
├── org.kde.kmdview.metainfo.xml
├── icons/                      # App icon (hicolor scalable)
├── src/                        # Application source
│   ├── main.cpp
│   ├── mainwindow.cpp
│   └── documenttheme.cpp
└── examples/sample.md          # Sample document for testing

Contributing

Bug reports and pull requests are welcome on GitHub Issues.

When submitting changes:

1. Fork the repository
2. Create a feature branch
3. Build and test locally
4. Open a pull request with a clear description of the change

License

KMDView is licensed under GPL-2.0-or-later, which is compatible with KDE applications and the wider free software ecosystem.

See LICENSE for the full text.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.