Microsoft Open Source: ASP.NET MVC, Web API, Razor

ASP.NET MVC, Web API, Razor and Open Source - ScottGu's Blog
Microsoft is serious about open source.

In addition to ASP.NET MVC that was already open source,
they have now added ASP.NET Web API and ASP.NET Web Pages (aka Razor)
under an open source license (Apache 2.0).

More from Scott Hanselman

http://aspnetwebstack.codeplex.com
http://asp.net/open-source