Swift on Windows without Visual Studio?

[sspringer (Stefan Springer)]

@SwiftButLazy

The natural fit would have been using the Clang toolchain as it is completely free, free from GNU stuff (what I know about) and also LLVM very much an Apple supported project.

The Microsoft compiler support should be optional instead for those who wants to import those libraries.

The LLVM based Swift toolchain is indeed used, albeit the situation is more complex, see this comment and this comment.