The Web Applications Working Group has published a First Public Working Draft of Service Workers. This specification describes a method that enables applications to take advantage of persistent background processing, including hooks to enable bootstrapping of web applications while offline. The core of this system is an event-driven Web Worker, which responds to events dispatched from documents and other sources. A system for managing installation, versions, and upgrades is provided. The Service Worker is a generic entry point for event-driven background processing in the Web Platform that is extensible by other specifications. Learn more about the Rich Web Client Activity.