Dublin: The current codename for the Windows Applications Server extension project which is the company's platform for distributing .NET applications in the cloud.
How it works? Microsoft's objective is to leverage its existing investment in the .NET Framework so that businesses can readily deploy applications, using the tools and resources they already own (including Visual Studio), on a cloud computing platform such as Windows Azure.
Dublin architecture asks developers to build "event handlers," borrowing a phraseology from another era of Windows programming, except that these events are generated by Web users, not by the end user of a GUI. These events are then handled through "virtual ports" that capture and interpret the events asynchronously, and then respond. While conceivably Dublin could deploy an existing .NET application to the cloud, you'd lose the point. Truly distributed applications respond to events that have been "published," and to which customers "subscribe" -- a signal which the application can recognize and accept. Using tools such as Workflow Foundation (WF), developers can build .NET code that responds to published events through what's called a service bus in Windows Communication Foundation. (This is the technology which Microsoft engineers predicted in 2004 would have already rendered IIS obsolete by now.) The result is an asynchronously behaving component that can be deployed as a component in a distributed composite application.
What it means? It is classic Microsoft to leverage its strengths in one area to build in another. It absolutely differentiates Microsoft's approach to cloud computing from its competitors in that it enables customers to build their own services to be deployed in the cloud, rather than 1) float an image of Windows Server in the cloud and pretend it's on-site; or 2) try to adapt someone else's cloud-based "out-of-the-cloud" application to suit their own purposes explicitly.