We're re-launching Signum Framework.

Is an Open Source (LGPL) framework for writing applications using a modular design, and taking advantage of the latest technologies from Microsoft (.Net 4.0/4.5.1, C# 5.0, LINQ, SQL Server, WPF, ASP.Net MVC 4.0/5.0 and TypeScript) and other popular web frameworks (jQuery, Bootstrap and D3.js), to provide a complete solution to Line-of-Business application.

In http://signumsoftware.com/en/Extensions there are examples of reusable modules that can be plugged in any Signum Framework application, including the necessary tables entities, business logic and windows/web user interfaces.

You can create an example application in http://signumsoftware.com/en/DuplicateApplication.