Quarkdown is a Turing-complete extension of Markdown that transforms a single source project into multiple output formats including print-ready books, academic papers, interactive presentations, and static websites. Built on CommonMark and GFM foundations, it introduces functions, variables, conditional statements, and loops directly into Markdown syntax, creating a programmable typesetting system where content and logic coexist in readable documents. The rendering pipeline supports three output modes: paged output via paged.js for papers, articles, and books with proper pagination; slide output via reveal.js for interactive presentations; and plain continuous flow for Notion-style knowledge bases and static sites.
The standard library provides an expanding collection of layout builders, I/O operations, math functions, and control flow constructs that can be composed into complex document structures. Authors define custom functions and variables within their Markdown files, enabling reusable components, dynamic content generation, and conditional sections based on output target. A VS Code extension powered by a dedicated language server delivers syntax highlighting, intelligent completions, live in-editor preview, documentation browsing, and real-time diagnostics. The project wiki at quarkdown.com/wiki is itself built with Quarkdown, serving as both documentation and a production demonstration of the system's capabilities.
Written in Kotlin and requiring Java 17+, Quarkdown has accumulated over 10,300 GitHub stars under the GPL-3.0 license. The project maintains an active release cadence with features like multi-file projects, bibliography management, and cross-reference linking added in recent versions. It occupies a unique position between simple Markdown renderers like Docusaurus and full typesetting systems like LaTeX, offering programmatic power without abandoning Markdown's readability. The single-source multi-output approach makes it particularly valuable for technical authors who need to maintain documentation, presentations, and published papers from one canonical source.
