Chrome 40 Beta Brings Service Workers
The main feature introduced in the Chrome 40 Beta is support for Service Workers, a new API for allowing web developers to improve the offline support of their web applications/sites. The Server Workers API allows for intercepting network requests to deliver programmatic or cached responses to help in offline situations or in delivering greater performance by caching common resources. Chromium 40 Beta also has new Fetch and Cache APIs for use within Service Workers.
Chromium 40 Beta also has new directives added in Content Security Policy Level 2, support for the minlength attribute, HarfBuzz support on OS X, and a variety of other additions and tweaks.
More details on today's Google web browser update can be found via the Chromium Blog.