Markzen

Write it once, hand it off as anything.
Read 8 markup languages, render 30 live extensions, export to 20+ formats.

Website  ·  Install  ·  Features  ·  Documentation  ·  Compatibility  ·  Development

_{Help in 28 languages}

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Install

Windows	macOS	Linux
x64 installer	Intel and Apple Silicon	portable AppImage

Windows note: SmartScreen may warn on first launch because the app is not code-signed. Click "More info", then "Run anyway".

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Features

Markzen is a cross-platform desktop editor for lightweight markup. You write in Markdown (or AsciiDoc, reStructuredText, Org, Textile, Djot, MediaWiki, BBCode), see a styled preview update live as you type, and export the result to any of 20+ document formats through a bundled Pandoc - without leaving the app. It is equally a viewer: open a file, collapse the editor pane, and read it as a rendered document.

• Eight markup languages, read live - Markdown, AsciiDoc, reStructuredText, Org, Textile, Djot, MediaWiki and BBCode, chosen by the file's extension, with no conversion step.
• 30 live figures from fenced code blocks - diagrams, charts, maths, music scores, chess and Go boards, QR codes, chemical structures.
• Export to 20+ formats - ebook, Word, OpenDocument, PowerPoint, reveal.js, LaTeX, Typst, Jupyter - or convert straight to another markup language.
• A real editor - full CodeMirror with syntax highlighting, formatting shortcuts and search, beside a preview that keeps up as you type.
• Tables without the syntax - pick a size from a grid, or paste spreadsheet cells and get a native table.
• Typeset typography - separate fonts for headings, body and code, plus five style templates.
• Table of contents - built from your headings, always in sync, click to jump.

Every extension, every file extension and every per-language limit is listed under Compatibility.

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Documentation

User manual	Read it online
Printable PDF	attached to each release
What's new	Release notes
Product page	apps.yaiol.com

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Build from source

npm install
npm run electron:dev   # React + Electron together (dev)

Requires Node.js 20+.

npm run dist        # Windows x64 installer
npm run dist:mac    # macOS DMG
npm run dist:linux  # Linux AppImage

Document export (DOCX/PDF/HTML) uses pandoc, which is not committed to the repo. The dist commands download it automatically (into vendor/pandoc/) before packaging. To test export in dev mode, fetch it once with npm run ci:prepare.

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Architecture

Markzen is an Electron app: a React renderer (built with Vite) over an Electron main process that also runs a small local Express server for file and export operations. There is no database - the renderer talks to the main process over local HTTP, and UI state persists in localStorage. The only preload exposure is a single webUtils.getPathForFile helper used to resolve dropped files; there is no IPC bridge.

Layer	Technology
UI framework	React 19
Bundler	Vite 8
Editor	CodeMirror 6
Desktop shell	Electron 41
Local API	Express 5
Markdown rendering	showdown
AsciiDoc rendering	asciidoctor
Math	KaTeX
Diagrams / charts / scores	Mermaid, Chart.js, VexFlow, … (30 extensions)
Document export	bundled Pandoc
Packaging	Electron Builder

Format adapters

The renderer is built around a format registry (src/formats/index.js). Each of the eight markup languages is an adapter - markdown, asciidoc, rst, org, textile, djot, mediawiki, bbcode - exposing a uniform interface (file extensions, editor shortcuts, a toHtml(text) pass, and an async postRender(el) pass). The active format is chosen by the open file's extension, or manually. Markdown is the default and fallback.

Rendering is two-phase: each adapter first converts source text to HTML (Markdown goes through showdown; the other formats through their own libraries, e.g. asciidoctor), then runs each registered extension's DOM render pass over the mounted preview.

Rendering extensions

The 30 extensions (src/formats/extensions/) turn a fenced code block - tagged with a language id after the triple backticks - into a live diagram, chart, score, math formula, or widget. They cover diagrams (Mermaid, Graphviz, Cytoscape, PlantUML, …), charts (Chart.js, Vega-Lite, ECharts, Plotly, …), math (KaTeX, AsciiMath), music notation (ABC, VexFlow, MusicXML, ChordPro), and more (chess, Go boards, QR codes, SMILES). Each extension is a small module with an HTML-injection step and a DOM render step, wired into the adapter's render chain.

Export pipeline

Export and format conversion run in the Electron main process through a bundled Pandoc binary (vendor/pandoc/, flattened into the packaged app's resources). Two surfaces use it, and what they hand Pandoc differs. Native export (EPUB, Word, OpenDocument, PowerPoint, RTF - the NATIVE_EXPORT_FORMATS list in App.jsx) posts the rendered HTML, with extension figures flattened to images, so diagrams, formulas and scores survive into the output. Format conversion (LaTeX, Typst, reveal.js, DocBook, JATS, Jupyter, OPML, and every markup-to-markup target) posts the document's source text, so an extension block lands in the output as a plain code block rather than a figure. PDF, HTML, and print are produced directly from the rendered preview (/save-pdf, /save-html, /print).

BBCode is the one asymmetric format. Pandoc can write BBCode (it ships six forum dialects) but has no BBCode reader, so the two directions take different paths: exporting to BBCode goes through Pandoc like everything else (using bbcode_hubzilla, the only dialect that preserves real [h1] headings, tables, rules and images), while reading a .bbcode file uses Markzen's own parser in src/formats/bbcode/render.js. Converting a .bbcode document to another format therefore hands Pandoc the already-rendered HTML instead of the source. BBCode has no specification and every forum differs, so the parser is deliberately tolerant: it accepts the common spellings side by side ([list]/[ul], [s]/[strike], [h1]/[heading=1], [code]/[icode]/[noparse]) and leaves any tag it does not know as literal text rather than dropping it.

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Compatibility

What each markup language supports

Markup language	File extensions	Live figures	TOC	Formula in a sentence	Cannot express
Markdown	.md .markdown	all	yes	$…$	text alignment
AsciiDoc	.adoc .asciidoc .asc	all but style	yes	block only	strikethrough
reStructuredText	.rst .rest	all but style	yes	$…$	strikethrough
Org	.org	all but style	yes	$…$	left / right alignment
Textile	.textile	all but style	yes	block only	-
Djot	.dj	all but style	yes	$`…`	-
MediaWiki	.wiki .mediawiki .wikitext	all but style	yes	<math>	inline code, strikethrough, blockquote, alignment
BBCode	.bbcode .bb	all but style	yes	block only	-

style is the one extension not available everywhere - it applies CSS to the document itself, which only the Markdown adapter loads. The block is spelled with backticks in six languages, [code=<tag>]…[/code] in BBCode and <syntaxhighlight lang="<tag>">…</syntaxhighlight> in MediaWiki.

Cannot express is a property of the markup language, not of Markzen: where a language defines no notation, the toolbar button is disabled rather than writing a private dialect.

Rendering extensions

Category	Extension	Block tag	Engine	Notes
Diagrams	Mermaid	mermaid	mermaid 11.17.0	flowcharts, sequence, class, Gantt, ER, state
	Graphviz	graphviz	@hpcc-js/wasm 2.35.0	the DOT language
	Cytoscape	cytoscape	cytoscape 3.34.1	network graphs; interactive
	Markmap	markmap	markmap-lib 0.18.12	mind map from an outline
	Timeline	timeline	built-in	vertical event timeline
Software diagrams	Nomnoml	nomnoml	nomnoml 1.7.0	UML
	PlantUML	plantuml	plantuml.com	UML - needs an internet connection
	DBML	dbml	@dbml/core 10.1.1	database schema
Charts	Chart.js	chartjs	chart.js 4.5.1	bar, line, pie, radar
	Vega-Lite	vega-lite	vega-embed 7.1.0	declarative charts from JSON
	ECharts	echarts	echarts 6.1.0	large interactive charts
IT development	Pseudocode	pseudocode	pseudocode 2.4.1	typeset algorithms
	Tabulator	tabulator	tabulator-tables 6.5.2	sortable interactive table
	Bytefield	bytefield	built-in	bit / byte field layouts
	QR Code	qrcode	qrcode 1.5.4
	Railroad	railroad	railroad-diagrams 1.0.0	syntax diagrams
	WaveDrom	wavedrom	wavedrom 3.6.2	digital timing diagrams
Mathematics	KaTeX	katex	katex 0.18.4	also inline, per the table above
	AsciiMath	asciimath	asciimath2tex 1.5.0	plain-text maths
Graphs	function-plot	fnplot	built-in	function curves (custom canvas renderer)
	JSXGraph	jsxgraph	jsxgraph 1.13.2	interactive geometry
	Plotly	plotly	plotly.js-dist-min 3.7.0	scientific and 3-D charts
Sciences	SMILES	smiles	smiles-drawer 2.4.1	chemical structures
Music	ABC Notation	abc	abcjs 6.7.0	sheet music from plain text
	VexFlow	vexflow	vexflow 5.0.0	engraved staves
	VexChords	vexchords	vexchords 1.2.0	guitar chord diagrams
	ChordPro	chordpro	chordsheetjs 15.6.2	chords above lyrics
	MusicXML	musicxml	opensheetmusicdisplay 2.1.2	full scores
Games	Chess	chess	chess.js 1.4.0	board from a FEN position
	Go Board	goboard	built-in	9x9, 13x13, 19x19
Document	Markzen	markzen	built-in	invisible - figure placement / TOC override
	Style	style	built-in	invisible - document-scoped CSS, Markdown only

Both tables are hand-written and audited against the source by scripts/check-compat.mjs (npm run check:compat), which re-derives the file extensions, TOC support, per-format extension sets and engine versions from src/formats/ and package.json and reports any drift.

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License

Released under the MIT License.

_{Markzen is part of yaiol Applications.}