Using technologies like Apollo, rich internet application designers can bridge
the one shortcoming of online apps — what to do when the internet isn't
available? Need to edit a document mid-flight? Want to post your photos from the
subway? Currently, you’re out of luck. But with Apollo-based apps, you could
perform your edits offline and sync your data the next time you connect.
Today's web application like google's Docs & Spreadsheet, ZOHO and flickr require consistent internet connection. But with Apollo, you can finish your work with the web-application on/off line. Apollo stil in its infancy and aim at Flex developer. Apollo has two separate component, SDK for programmer and a runtime software for user to run it on Windows or MAC. You also can experience this with adobe's upcoming Creative Suite 3.
Watch this video to understand about Apollo