Oh, the old compiler is just the currently shipping compiler (i.e., the one in a clean install of VS 2013). We've been using and maintaining it since the beginn

Oh, the old compiler is just the currently shipping compiler (i.e., the one in a clean install of VS 2013). We've been using and maintaining it since the beginning. It's written in C++, so we refer to it as the "native compiler." We only stopped bootstrapping using the native compiler about, oh, 6 months ago, since that was when we decided to take a dependency on new language features. The next VS will be the first VS where Roslyn is the default C# compiler.