Lately I have been quite busy working on .NET 4.0 which will be the next major side-by-side release of .NET Framework since .NET 2.0. It will be unveiled at PDC on October 27th. .NET 4.0 will be shipped together with the next version of Visual Studio.

As you know, Windows Workflow Foundation (WF) and Windows Communication Foundation (WCF) were first released in .NET 3.0. WF enables data-driven programming, or “code as data” in Don’s words. WCF provides a service-oriented programming model which enables easy, secure, and reliable communications for distributed applications. In .NET 3.5, WF and WCF were first integrated together through WorkflowServiceHost and message activities. .NET 4.0 will contain major improvements in both WF and WCF. The two will be integrated seamlessly together from the programming model to the runtime. Workflows and services are tightly coupled and both can be declaratively modeled by XAML. With the significant performance improvements in the runtime, the new workflow framework will enable a broad spectrum of model-driven programming scenarios.

By mentioning “model-driven” programming, you will see a general modeling platform to be unveiled at PDC: Oslo. As Doug said, Oslo contains three “simple” things: a visual tool helps building models, a new textual DSL language helps defining models, and a relational repository that stores models. XAML represented workflows and services are special models in this domain. Check for more details in the postings from Doug and Don.

Hope that you will have fun in the PDC!