The next version of C# has been reimplemented from scratch in C#, with an open, complete, resilient and incremental language model. All IDE features are built on top of this public API and you can easily add your own – e.g. pluggable diagnostics and code fixes that fit your style and policies. The compiler is open source, and we’ve added a host of new language features. We’ll take a whirlwind tour through the layers of the new C# universe.