Markdown

Markdown is a plain text file format for creating structured documents. Files end in .md. You write headings with #, lists with -, bold with **, code with backticks. No special editor needed. Any text editor works.

Created by John Gruber in 2004. Now the default format for READMEs, documentation, notes, and wikis across the entire software ecosystem. GitHub, Notion, Obsidian, and thousands of other tools render it natively.

Why AI agents use it. Markdown sits in the exact sweet spot between human readability and machine parseability. AI models can read and generate markdown fluently. Every major agent runtime chose markdown as its configuration format independently: CLAUDE.md, AGENTS.md, .cursor/rules/. The format is structured enough to carry intent but flexible enough to carry judgment.

This page is in progress. Follow @NoahGreenSnow for updates.