Not many things in the software development field surprise me these days, in fact the only things that have seriously surprised me in recent years are a) how good the Marmalade SDK is and b) how HTML5 is not really my enemy. However Microsoft open sourcing .NET has hit me like a truck full of surprises. I’ve always been a fan of C# and .NET, which all of my tolls are built on, so this is lovely news.
The project home page is at http://www.dotnetfoundation.org/