Features

Cross-cutting capabilities — things that are not a single package but show up across multiple ones. These pages are the "trace this feature end to end" view of the runtime.

Pages

• Hooks — how a useState(0) call flows from react through the dispatcher to the reconciler and back, with a focus on what the team most often modifies.
• Concurrent rendering — lanes, transitions, deferred values, the cooperative work loop, the scheduler. The "how concurrent React really works" page.
• Suspense — Suspense boundaries, throwing thenables, hydration boundaries, retries, and the related Activity and <ViewTransition> primitives.
• Server Components — the full RSC pipeline: server tree → Flight stream → bundler manifest → client tree → DOM. Plus Server Actions.

Why these and not others

Many areas the team treats as "features" are localized enough that they live entirely inside one package's page:

• The DOM event system is in packages/react-dom.
• Resource hoisting (Float) is in packages/react-dom.
• The class component path is documented inline in packages/react-reconciler.
• Hot reloading / fast refresh is in packages/other-packages.

The four pages in this section are reserved for capabilities that genuinely span multiple packages and benefit from a single end-to-end narrative.