Until now, the VB and C# compilers have been used as black boxes. You put text in, and you get out a binary file. In our long-lead project, codename "Roslyn", we'll be changing that dynamic by building an API that exposes our compilers' analysis engines. In this session, we'll give an overview of the Roslyn project and share our early plans for the future version of the C# and VB compiler and language services. We'll look at object models that can be used for code generation, analysis, and refactoring, and upcoming support for scripting and interactive use of C# and Visual Basic.