GFM vs CommonMark vs Pandoc Markdown: Which Syntax Travels?
The same Markdown file renders differently on GitHub, Hugo, Obsidian, and Pandoc — not because Markdown is unreliable, but because “Markdown” names a family of syntaxes, parsers, and platform features. CommonMark defines the portable core, GFM adds software-collaboration extensions, and Pandoc Markdown expands into a full document language.