Roslyn (compiler) founded by Microsoft
.NET Compiler Platform, also known by its codename Roslyn, is a set of open-source compilers and code analysis APIs for C# and Visual Basic (VB.NET) languages from Microsoft.The project notably includes self-hosting versions of the C# and VB.NET compilers – compilers written in the languages themselves. The compilers are available via the traditional command-line programs but also as APIs available natively from within .NET code. Roslyn exposes modules for syntactic (lexical) analysis of code, semantic analysis, dynamic compilation to CIL, and code emission.Compilers for the C# and Visual Basic languages exposed as services via APIs.
APIs for code analysis and refactoring.