Microsoft delivers missing RIA tools, components for Silverlight 4
Windows Communication Foundation (WCF) RIA Services for Silverlight is one of those. On May 17, Microsoft delivered the final 1.0 release of that code, which adds support for Silverlight 4 and Visual Studio 2010.
WCF RIA Services simplifies the traditional n-tier application pattern by bringing together the ASP.NET and Silverlight platforms. RIA Services provides a pattern to write application logic that runs on the mid-tier and controls access to data for queries, changes and custom operations. It also provides end-to-end support for common tasks such as data validation, authentication and roles by integrating with Silverlight components on the client and ASP.NET on the mid-tier.