MDX

MDX is Markdown with JSX superpowers. Write normal Markdown, and when you need something dynamic, import a React component and use it inline.

That's the whole pitch. MIT licensed, used by Docusaurus, Next.js docs, Gatsby, and half the documentation sites on the internet. It's the standard for component-enhanced content.

Fully free. No paid tier, no hosted service. It's a compiler that transforms your .mdx files into JavaScript. Works with every major framework: React, Vue (via plugins), Svelte, and more.

The catch: MDX adds build complexity. Your content now depends on a JavaScript build pipeline. You can't just render Markdown server-side anymore. Debugging MDX compilation errors is painful, especially when you mix complex JSX with Markdown. And if your content team isn't comfortable with JSX syntax, they'll hate it. For pure Markdown with no interactivity, stick with regular .md files.