The first time I’ve heard about .NET RIA Services was only a couple of weeks ago, when a colleague of mine (thanks Rui Rasteiro) introduced me to this pattern he was trying it out.
Microsoft .NET RIA Services simplifies the traditional n-tier application pattern by bringing together the ASP.NET and Silverlight platforms. The 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.
It is basically a pattern to implement N-tier architectures (with N tending to 3) on RIA apps, targeting rich the presentation layer for Silverlight (and ASP.NET), decoupling the physical data stores by the introduction of ADO.NET DataServices, articulated through an application mid-tier which can focus on domain logic as the plumbing solves:
[…] write application logic on the server and display, validate the data, as well as supporting authorization, querying, sorting, filtering, paging, etc, not to mention providing a clean way to mock out the data layer to do testing (a la TDD, etc). All regardless of what data store you use (Entity Framework, Linq2Sql, nHibernate, Xml file, REST service, WCF-server, etc).
Here’s the roadmap:
July 2009 CTP
PDC 2009 Beta
First part of 2010: RTW