Quarto is an open-source scientific and technical publishing system built on Pandoc, designed to create reproducible documents by combining code, output, and narrative text. It supports multiple languages (Python, R, Julia, Observable JS) and renders to various formats (HTML, PDF, Word, slides, dashboards, websites, books) from a single source. Unlike R Markdown, Quarto is language-agnostic with native multi-format support and doesn't require R as a dependency. The key insight: Quarto treats documents as executable markdown where computational results are embedded directly into the output, making it ideal for parameterized reports, automated workflows, and reproducible research at scale.