Marker Is A Powerful Gtk3 Markdown Editor

Marker is a free and open source GTK3 Markdown editor designed with the Gnome desktop in mind. While the application is still in early development, it already includes most of the things you'd need in a Markdown editor.

Marker Markdown editor

The application tries to provide a powerful document editing experience while using a simple interface with enough customization to meet most needs.

Besides basic Markdown features, Marker also includes:

  • Live HTML preview
  • HTML and LaTeX conversion of markdown documents with SciDown
  • TeX math rendering with KaTeX and MathJax
  • Support for Mermaid flow charts, sequence diagrams, and gantt diagrams
  • Support for Charter scatter plots, bar graphs, and line graphs
  • Syntax highlighting for code blocks using highlight.js
  • Integrated sketch editor window, useful for adding hand-drawn diagrams and signatures to documents
  • Custom CSS themes
  • Custom syntax themes
  • Export to HTML, PDF, RTF, ODT, DOCX, and LaTeX

Marker markdown editor sketch
Marker and its integrated sketch editor

The Marker user interface is very simplistic and doesn't offer any Markdown formatting tools - for that, you must use keyboard shortcuts or type the code directly into the editor.

By default, Marker uses a dual pane mode, with the Markdown editor and live preview modes side by side, while also allowing the user to change it to code editor only, preview only, or a dual window mode.

In my opinion, the user interface is Marker's weakest point right now. Not because it's simplistic, I actually like that part. But because it lacks some features I personally (and thus, I might be in a minority here) enjoy in a Markdown editor. For example, Marker doesn't scroll both the code and live preview in the dual pane mode when scrolling one of them, so to have the same part of a document in both views, you must scroll both panes manually. There's no focus mode either, a feature I would very much enjoy and use. A seamless live preview (in which the Markdown editor and HTML preview are integrated in a single view, similar to Mark Text) feature would be awesome to have as well.

Not having all these features is understandable though, as application is relatively new, with the first version being released in September, 2017. There's also a warning on the application GitHub page mentioning that the tool is in early development and there may be bugs and unfinished features.

The application does have a dark theme mode though, which I for one appreciate.

From the Marker preferences, users can choose to show line numbers, wrap text, show spaces, or enable spell checking, which is disabled by default. Automatic tab indentation, insert spaces instead of tabs, and the tabulation width can also be changed from here.

You can also change the editor syntax highlight theme, code blocks theme or preview CSS theme, enable advanced features like Mermaid or Charter, and switch between KaTeX or MathJax for the math render.

Marker was updated earlier this week, receiving the following improvements:

  • Added the ability to export documents from the command line
  • Added vim-like shortcuts (h, j, k, l, g, G) to the previewer
  • Added the ability to open Marker in any view mode from the command line

To view the Marker command line options when the application is installed from FlatHub (Flatpak), use:

flatpak run com.github.fabiocolacio.marker --help

Download Marker

The Marker Markdown editor source is available on GitHub.