Sane aims to be fast, small, and reliable file system watcher. It does that by: * By default stays away from fs polling because it's very slow and cpu intensive * Uses `fs.watch` by default and sensibly works around the various issues * Maintains a consistent API across different platforms * Where `fs.watch` is not reliable you have the choice of using the following alternatives: * the facebook watchman library (embedded) * the watchexec library (embedded) * polling