Future managed C# and VB compiler and language services API from Microsoft
In a future release of Visual Studio, C# and Visual Basic compilers and language services will be completely rewritten from scratch in managed code, with a clean and powerful managed API.
This effort is code-named 'Roslyn', and the managed compiler + services API will be available to all consumers. Roslyn API will expose all stages of the compiler pipeline: you will be able to use the C#/VB parser to create syntax trees from text, transform trees using Visitors, get the semantic information and bind nodes to symbols, and generate IL assemblies from syntax trees and assembly references to disk or to an in-memory stream.