• Generating HTML5 AppCache Manifests with Fiddler - Fiddler Web Debugger - Site Home - MSDN Blogs
  HTML5 introduces the concept of an Application Cache, which allows a web developer to provide a manifest of pages that should be cached to permit offline use. You can see an instance of AppCache over on the IETestDrive site; if you examine the markup, you can find that the HTML tag contains a manifest attribute which specifies the URI of the AppCache manifest.
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• HTML5 Rocks - A Beginner's Guide to Using the Application Cache
  It's becoming increasingly important for web-based applications to be accessible offline. Yes, all browsers have caching mechanisms, but they're unreliable and don't always work as you might expect. HTML5 addresses some of the annoyances of being offline with the ApplicationCache interface.
  in Development > Mobile Web Apps with appcache cache html5

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