The vision of application development that Microsoft promoted before the release of the Vista update to Windows relied on a three-part promise of superior communications, superior interactive graphics and a superior model of client-side storage. Delivering that combination, known at one time as the "three pillars of Longhorn," would have encouraged developers to think in terms of a rich Windows-specific application that exploited the client-side platform to define and deliver the user experience—while calling out to the Internet cloud for data and background services.
That was a powerful vision, but it was not delivered in anything like the time frame promised, nor were all of the pieces put together to complete the picture that had been so attractively drawn. The focus of developers has therefore shifted into the cloud itself, sometimes combined with client-side cross-platform logic using mechanisms such as AJAX—and decoupling application access from client-side platform choice.