# react/jsx

The JSX specification is a XML-like syntax extension to ECMAScript.

Repository: https://github.com/react/jsx
Canonical: https://ross.abutalabs.com/products/jsx
Homepage: http://react.github.io/jsx/
Language: HTML
License Family: other
Last push: 2023-11-27T14:17:19+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4388, "days_push": 1010, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1999, forks 130 (observed 2026-08-28T04:06:03.776245+00:00)

## What it is
The JSX specification defines an XML-like syntax extension to ECMAScript for expressing tree structures with attributes, intended to be consumed by preprocessors and transpilers rather than engines or browsers. It is a draft specification document, not an implementation, that lets independent parsers, transpilers, and syntax highlighters conform to a single syntax standard.

## Use cases
- implement a JSX parser or transpiler
- understand the JSX grammar and syntax rules
- build a syntax highlighter for JSX
- design a new JavaScript syntax extension compatible with JSX
- check how JSX attributes and children are formally defined

## When to choose
- you are building a compiler, parser, or linter that must handle JSX
- you need the authoritative grammar for JSX tokens and strings
- you want to align a custom syntax extension with JSX conventions

## When to avoid
- you want a runnable JSX compiler or runtime - use Babel, TypeScript, or esbuild instead
- you want to learn React component development rather than the syntax spec
- you need executable code or a library to install

## Facets
- artifact type: learning-resource
- maturity: maintenance
- function: parser, documentation, programming-language
- domain: frontend, web-development, programming-languages, documentation
- platform: -
- tags: jsx, specification, syntax-extension, ecmascript, transpiler-target, react, javascript, web

## Member repositories
- react/jsx (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:03.776245+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:02:11.246512+00:00, confidence not recorded.
  - readme: https://github.com/react/jsx (fetched 2026-08-28T04:06:03.776245+00:00, sha c250af487e73)
  - homepage: http://react.github.io/jsx/ (fetched 2026-08-29T10:41:52.968548+00:00, sha a077ca618f5f)
- Data as of 2026-08-30T08:39:29.467469+00:00.