MarkUP#

MarkUP is a markup language based on Markdown. It adds directives — named components with a label, attributes and a body — so that documents can contain callouts, tabs, charts and other structure without raw HTML.

:::warning[Before tagging a release]
Run `npm run check` and update `CHANGELOG.md`.
:::

| Step  | Command         |
|-------|-----------------|
| Test  | `npm test`      |
| Build | `npm run build` |

Press :kbd[Ctrl+S] to save. Status: :badge[stable]{variant=success}

Everything that is valid Markdown in the usual sense — headings, emphasis, lists, links, code, tables, footnotes — works the same way. Directives use one syntax in three forms:

Properties of the language#

• Parsing never fails. Every input produces a complete syntax tree. Problems are reported as diagnostics with a code, a line and column, and often a fix that editors can apply.
• No raw HTML. <div> is text. Documents stay independent of the output format, and previews of untrusted documents are safe.
• Components are declared, not hard-coded. A component is a specification — name, forms, label, typed attributes, content model — plus a render function. The parser only reads the specifications; plugins add new components without changing it.
• Positions everywhere. Every node of the tree carries its source range, which is what the editors use for highlighting, outline and scroll sync.

Tools#

All three use the same packages: @markup-lang/core (parser, validation), @markup-lang/html and @markup-lang/text (renderers) and @markup-lang/language-service (editor features). See Architecture.

Next steps#

• Installation — the desktop app, the VS Code extension and the CLI.
• Quick start — write, preview, check and build a first document.
• Syntax — the language, construct by construct.
• Components — every built-in component with its attributes.
• Specification — the precise rules, for implementers.