Two interesting blog posts about releasing some of the .Net libraries as Open Source licensed code.
We’ll begin by offering the source code (with source file comments included) for the .NET Base Class Libraries (System, System.IO, System.Collections, System.Configuration, System.Threading, System.Net, System.Security, System.Runtime, System.Text, etc), ASP.NET (System.Web), Windows Forms (System.Windows.Forms), ADO.NET (System.Data), XML (System.Xml), and WPF (System.Windows). We’ll then be adding more libraries in the months ahead (including WCF, Workflow, and LINQ). The source code will be released under the Microsoft Reference License (MS-RL).
You’ll be able to download the .NET Framework source libraries via a standalone install (allowing you to use any text editor to browse it locally). We will also provide integrated debugging support of it within VS 2008.
This release falls under Microsoft’s Shared Source Initiative, which encompasses a spectrum of source code offerings, complementing the company’s other activities around sharing source code. This is another example of Microsoft’s continued commitment to increasing transparency and addressing developer needs.

Dogs and Cats Living Together, Mass Hysteria!