||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.