The Service Workers Working Group has published a Candidate Recommendation of Service Workers 1. 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.
Comments are welcome by 31 January 2020.