Why Markdown Became the Developer's Writing Format

John Gruber created Markdown in 2004 with a simple goal: write in plain text that reads naturally and converts to valid HTML. It succeeded because the syntax is intuitive — asterisks for emphasis, hashes for headings, hyphens for lists — and the source file is readable without rendering. Today, Markdown is the default format for GitHub READMEs, documentation sites (Docusaurus, MkDocs, VitePress), note-taking apps (Obsidian, Notion), and static site generators (Astro, Hugo, Jekyll).

GitHub Flavored Markdown (GFM)

Standard Markdown lacks tables, task lists, and strikethrough. GitHub Flavored Markdown (GFM) extends the spec with these features plus fenced code blocks with syntax highlighting, autolinked URLs, and emoji shortcodes. GFM has become the de facto standard — most Markdown processors support it, and the CommonMark specification (which standardized the ambiguities in original Markdown) has influenced GFM's parsing rules.

Markdown to HTML: What Happens Under the Hood

Markdown processors parse the source text into an Abstract Syntax Tree (AST), then render the AST to HTML. Libraries like remark (JavaScript), markdown-it (JavaScript), and Python-Markdown expose the AST, allowing plugins to transform content — adding syntax highlighting, table of contents, math rendering (KaTeX/MathJax), and custom components. This plugin architecture is why Markdown powers complex documentation sites despite its simple syntax.