CSLA.NET is a framework which enables you to create a object oriented business layer that abstracts and encapsulates business logic and data. The recent release, CSLA 4 version 4.5, includes support for WinRT and includes significant enhancements to the business rules engine.
CSLA provides support for Windows Forms with the help of Csla.Windows namespace. It enables you to work with the new async and await keywords with the ability to make use of these keywords in .NET Framework 4 using async targeting pack.
The framework also provides support for .NET Framework 4.5, .NET Framework 4, Silverlight 5 and provides an ability to recompile existing CSLA business classes for WinRT without any major modifications.
CSLA enables you to implement, manage and reuse business logic for WPF, ASP.NET MVC, ASP.NET Web Forms, WCF, Windows Phone 7, Silverlight, Windows Workflow and Windows Forms applications including support for Linux, Mac, iPhone, iPad and Android platforms.
Rockford Lhotka, Creator of the CSLA .NET has documented the features and usage of the framework in his ebook series.