Markdown Reader

A GNOME desktop app for reading, editing and previewing Markdown files, written in Rust with GTK 4, libadwaita and WebKitGTK.

Features

• Preview with GitHub-flavoured Markdown: tables, task lists, footnotes, alerts (> [!NOTE]), emoji shortcodes, syntax-highlighted code, and front matter hidden.
• HTML inside Markdown, sanitised the way GitHub does it: <details>, <kbd>, <sub>, <img width>, <p align="center"> work; scripts, styles and event handlers are removed.
• Math ($…$, $$…$$, ```math) rendered with KaTeX.
• Diagrams (```mermaid) rendered with Mermaid.
• Edit mode (Ctrl+E): side-by-side editor and live preview, scrolled in sync line by line in both directions. Long lines wrap.
• Search (Ctrl+F): in edit mode it steps through matches in the editor and highlights them in the preview; Escape leaves the match selected.
• Contents sidebar (F9) built from the headings.
• Print (Ctrl+P), Export as PDF, Export as HTML (a single self-contained file with images embedded).
• Follows links between Markdown files (with Back, Alt+Left), reloads when the file changes on disk, and remembers the window layout between sessions.
• Works offline: KaTeX and Mermaid are bundled into the binary.

Building

Requires GTK ≥ 4.14, libadwaita ≥ 1.5, WebKitGTK 6.0 ≥ 2.40 and GtkSourceView 5, so it builds on Fedora 40+, Ubuntu 24.04+ and Debian 13+ (Ubuntu 22.04 and Debian 12 ship libraries that are too old).

Fedora:

sudo dnf install gcc pkgconf-pkg-config gtk4-devel libadwaita-devel webkitgtk6.0-devel gtksourceview5-devel

Debian 13 / Ubuntu 24.04 (and derivatives such as Linux Mint 22, Pop!_OS 24.04):

sudo apt install build-essential pkg-config libgtk-4-dev libadwaita-1-dev libwebkitgtk-6.0-dev libgtksourceview-5-dev

Then, with a Rust toolchain (1.85+, e.g. from rustup):

cargo build --release

Installing

./install.sh               # build, install to ~/.local, set as the default .md app
./install.sh --no-default  # same, but leave the default app alone
./install.sh --uninstall

Run it with mdreader [FILE…] or mdreader --new.

Keyboard shortcuts

Keys	Action
Ctrl+O / Ctrl+N	Open / new document
Ctrl+S / Ctrl+Shift+S	Save / save as
Ctrl+E	Toggle edit mode
Ctrl+F, Ctrl+G, Ctrl+Shift+G	Find, next, previous
F9	Contents sidebar
Alt+Left	Back
Ctrl+P	Print
Ctrl+Plus / Ctrl+Minus / Ctrl+0	Zoom
Ctrl+W / Ctrl+Q	Close window / quit

Bundled libraries

vendor/ holds KaTeX and Mermaid, both MIT-licensed (licences included). vendor/update.sh re-downloads them and rebuilds KaTeX's self-contained stylesheet.

Licence

MIT, see LICENSE.