Today we released the betas for VS2008 sp1 and .NET 3.5 sp1. Scott did a good job (as usual :-)) running through the top-level enhancements, so I won't parrot it all here.. but I'd like to go through the next level of detail on what new goodies we have for service developers. The most interesting/exciting feature for service developers is what we call Data Services (previously known as "Astoria"). The best way to explain how Data Services fits into the overall "services platform" that .NET provides is through a picture: As a service developer, .NET offers me a layered stack - if I want to write "to the metal", I can build a service on top of System.Net and HttpListener (which is a managed wrapper on top of HTTP.SYS - our kernel HTTP driver). Not many people end up doing that, because there are lots of good pieces that we've already written for you.. WCF provides the next layer. WCF gives you some modular pieces, such as channels (HTTP, TCP, MSMQ, etc); Serialization, which is a fancy word for pouring objects into a serialized formats such as XML, binary, JSON, and deserializing back into objects; and what we call "Syndication", which are some classes that support various data publishing microformats such as RSS and ATOM. Finally, we have a layer called Service Model that ties all of this stuff together in a coherent, approachable programming model. WCF is a powerful but general framework, so the next layer up consists of particular scenarios that we wanted to significantly simplify. I think of two canonical scenarios for writing services: "resource-oriented" services, where you model your service as a bunch of resources and offer request/response, HTTP-based access to those resources; and "operation-oriented" services, where you want to create a new "operation" that wraps a more involved operation that often has to coordinate state changes across multiple resources. Operation-oriented services become more attractive the more asynchrony you need in your service implementation.. the canonical example is "book a trip" which in turn composes other asynchronous services, such as "book the airfare", "book the hotel", etc. We realized that most operation-oriented services are actually most easily modeled as workflows.. and that's why we invested heavily in .NET 3.5 in Workflow Services, which is a pretty deep integration between WCF and Workflow. Resource-oriented services became easier to write in .NET 3.5 via our REST support that we added to WCF. But we thought
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