Back in October, Microsoft released the first Community Technology Preview (CTP) test build of "Roslyn" compiler as a service technology, that previews the "next generation of language object models for code generation, analysis, and refactoring, and the upcoming support for scripting and interactive use of VB and C#."
"Traditionally, compilers are black boxes - source code goes in one end and object files or assemblies come out the other end. The Roslyn project changes that model by opening up the Visual Basic and C# compilers as APIs. These APIs allow tools and end-users to share in the wealth of information the compilers have about code."
In the video below, the Roslyn Project design team (and the authors of the The Roslyn Project technical paper), Anders Hejlsberg, Karen Liu, Matt Warren, and Peter Golde discuss why Roslyn matters, how it works (briefly - we'll go deeper in the future), what it affords, and what it doesn't enable.