react-native-restart is a small React Native native module that programmatically reloads the running JS bundle at runtime — a full process restart on Android, a bundle reload in-process on iOS and Windows. The architecture is a deliberately thin TypeScript bridge (src/index.tsx) over three native implementations, all registered under the module name RNRestart. The JS layer resolves the native module through TurboModuleRegistry on the New Architecture with a NativeModules fallback for the legacy bridge, and throws a descriptive linking error when the module was never linked. A TurboModule spec (src/NativeRNRestart.ts) drives RN codegen on Android and Windows. The public API is just three calls: restart(reason?), the deprecated Restart(reason?) alias, and getReason() which returns a reason that survives the restart.
Rerun is a command-line utility that automatically restarts a program when relevant files in a watched directory change. It wraps the Listen gem to efficiently monitor the filesystem and supports graceful process termination via configurable signal sequences (default TERM, INT, KILL). The tool provides real-time keypress commands (restart, force restart, clear, pause, quit) and optional desktop notifications via growlnotify, terminal-notifier, or notify-send. The codebase is a single Ruby gem with a CLI entry point (bin/rerun) and a clear separation of concerns: Runner for process management, Watcher for filesystem listening, Options for CLI parsing, and Notification for cross-platform alerts. It was last actively developed around 2014-2018, with a documented version 0.14.0 in 2023, but open issues and pull requests from 2014 suggest it is no longer maintained.