The idea is by no means new. localStorage is old. So is the AppCache specifications that actually allows an application to go 'offline'. Gmail did this as early

The idea is by no means new. localStorage is old. So is the AppCache specifications that actually allows an application to go 'offline'. Gmail did this as early as 2009: http://googlecode.blogspot.sg/2009/04/gmail-for-mobile-html5-series-using.html http://googlecode.blogspot.sg/2009/04/gmail-for-mobile-html5... Unfortunately it's not as easy as it looks. I found that out when doing research for a weekend project. Here's an excellent A List Apart article detailing all the gotchas you can face while working with it: http://www.alistapart.com/articles/application-cache-is-a-douchebag/ http://www.alistapart.com/articles/application-cache-is-a-do.... The Financial Times Labs have an interesting article talking about an approach to deploying an offline app that uses the AppCache as little as possible: http://labs.ft.com/2012/08/basic-offline-html5-web-app/ http://labs.ft.com/2012/08/basic-offline-html5-web-app/ And of course you can find information about it in places like Dive into HTML5 and MDN, by simply searching for them