Out-of-Tree Platform

An out-of-tree platform is a React Native target that lives outside the main facebook/react-native repository. Core React Native ships iOS and Android; other targets are built and released separately by companies or the community, reusing React and the core renderer while supplying their own host platform implementation.

The best-known examples:

• React Native Windows and React Native macOS, maintained by Microsoft for desktop apps.
• react-native-tvos, a community-maintained fork that adds Apple TV and Android TV support, including focus-based navigation for remotes.
• React Native visionOS, a community project for Apple Vision Pro.

React Native Web is related but different: it reimplements React Native’s components on top of the DOM rather than plugging a native platform into the core renderer.

In practice an out-of-tree platform behaves much like iOS and Android from your code’s point of view. Platform.OS reports values such as 'windows' or 'macos', and Metro can resolve platform extensions like Button.windows.tsx, so platform-specific code works the same way.

The gotchas are about timing and libraries:

• Out-of-tree platforms follow core releases, so a new React Native version may take a while to be supported there. Check before upgrading.
• Third-party native libraries only work on a platform if their authors added native code for it. A package that supports iOS and Android often has no Windows or macOS implementation.
• react-native-tvos is installed in place of react-native, usually through a package alias in package.json, rather than alongside it.

Check each library’s supported platforms before committing to a desktop or TV target.