I spent some time over the past few days using my prototype Silverlight serializer to build a prototype Silverlight data portal. It is still fairly far from complete, but at least I've proved out the basic concept and uncovered some interesting side-effects of living in Silverlight. The good news is that the basic concept of the data portal works. Defining objects that physically move between the Silverlight client and a .NET web server is practical, and works in a manner similar to the pure .NET data portal. The bad news is that it can't work exactly like the pure .NET data portal, and the technique does require some manual effort when creating the business assemblies (yes, plural). The approach I'm taking involves having two business assemblies (VS projects) that share many of the same code files. Suppose you want to have a Person object move between the client and server. You need Person in a Silverlight class library and in a .NET class library . This means two projects are required, even if they have the same code file. Visual Studio makes this reasonable, because you can create the file in one project (say the Silverlight class library) and then Add Existing Item and use the Link feature to get that same file included into a .NET class library project. I also make the class be a partial class, so I can add extra code to the .NET class library implementation. The result is: BusinessLibrary.Client (Silverlight class library) -> Person.cs BusinessLibrary.Server (.NET class library) -> Person.cs (linked from BusinessLibrary.Client) -> Person.Server.cs One key thing is that both projects build a file called BusinessLibrary.dll . Also, because Person.cs is a shared file, it obviously has the same namespace. This is all very important, because the serializer requires that the fully qualified type name ("namespace.type,assembly") be the same on client and server. In my case it is "BusinessLibrary.Person,BusinessLibrary". The Person.Server.cs file contains the server-only parts of the Person class - it is just the rest of the partial class. The only catch here is that it can not define any fields because that would obviously confuse the serializer since those fields wouldn't exist on the client. Well, actually it could define fields as long as they were marked as NonSerialized. Of course you could also have a partial Person.Client.cs in the Silverlight class library - though I haven't found a need for that just yet. One thing I'm debating is whether the Read More...