Visibility.js

Visibility.js is a lightweight JavaScript library providing a robust wrapper around the native Page Visibility API, abstracting away vendor prefixes and offering enhanced utility functions. The current stable version is 2.0.2, with recent updates focusing on modernizing its distribution (removing support for legacy package managers in 2.0.0) and improving TypeScript definitions. Its core strength lies in intelligent timers and event handlers: `Visibility.every` creates timers that automatically pause or adjust intervals when a page is hidden, optimizing resource usage, while `onVisible` and `onHidden` provide direct callbacks for state changes. A key differentiator is its built-in fallback for older browsers, although this feature has a known limitation when a browser window loses focus but remains visible.