Open Source – WinJS, Roslyn and Comanche054/Luminary099
So by far the coolest of these has to be the open sourcing of Apollo 11 Command Module code (Comanche054) and Lunar Module code (Luminary099)
More up to date, will WinJS make headway in the non Windows space?
To wrap up, there’s .NET Compiler Platform (“Roslyn“)
The .NET Compiler Platform (“Roslyn”) exposes a set of Compiler APIs and Workspaces APIs that provides rich information about your source code and that has full fidelity with the C# and Visual Basic languages. The transition to compilers as a platform dramatically lowers the barrier to entry for creating code focused tools and applications. It creates many opportunities for innovation in areas such as meta-programming, code generation and transformation, interactive use of the C# and VB languages, and embedding of C# and VB in domain specific languages.