Google unleashed the offline access to Gmail, Google Calendar and Google Docs. With the Chrome Apps these can be access even without the internet connection. Thanks to the HTML5 which Google used to build these Apps.
Gmail offline Apps is now available to install, starting today at Chrome web store while the Google Calendar and Google Docs will be roll-out in the coming week. These HTML5-powered app is based on the Gmail web app for tablets, which was built to function with or without web access. With Google Calendar and Google Docs it would be easy to toggle between on and offline modes. Unfortunately like viewing the events RSVP to appointments, documents and spreadsheets Google has not come with offline editing for them.
Google has it Chrome OS and Chrome web browser which mean to compete in the market. With the offline capable Apps Google is supporting it Chrome Book. Also these effort is part of Google support or favor for the HTML5.
Source: Gmail Blog