Another good example of "compiler as a service" is the Roslyn compiler for C# (and also written in C#). What is interesting is that Roslyn was a complete rewri

Another good example of "compiler as a service" is the Roslyn compiler for C# (and also written in C#). What is interesting is that Roslyn was a complete rewrite compared to the original C# compiler (which was written in C++ and couldn't power an IDE, so the tools like Resharper had to implement their own compiler front-end, essentially). IIRC, the ability to evolve the language was also a factor. It seems that as the language matures, there comes a point where tooling (and further evolvability!) becomes important enough to justify the huge undertaking of rewriting the entire compiler. I wonder when will Rust reach that phase...