Beginning Adobe® AIR™: Building Applications for the Adobe Integrated Runtime

1.1. Online versus Desktop Applications

The traditional definition of an online application is one that runs within a web browser while connected to the Internet. A desktop application has traditionally been one that runs on the local computer whether there is an Internet connection or not. New programming models like AIR have begun to blend these ideas and create hybrid applications in which some of the data are stored locally, while additional data may be loaded into the application when an Internet connection exists. Or the application can synchronize its data or files when an Internet connection exists for use later when an Internet connection no longer exists. Google via its Gears API has also begun to create browser-based applications that can cache data within an embedded database for offline use.

There is no doubt that the convergence of online and desktop applications into occasionally connected applications will continue. With tools such as AIR, it is easier than ever to create applications that can perform well whether an Internet connection exists or not.

1.1.1. The Runtime Environment

The runtime environment is what guarantees the consistent experience across different operating systems and the versions of each. For example, there is an API within an AIR application that handles the creation of a new file or folder. The AIR developer writes the application using this API. The runtime then translates this request into an operating-system-specific call, ensuring that ...