Swift is a modern language based upon the LLVM compiler framework. It takes advantage of Clang to provide seamless interoperability with C/C++. The Swift compiler and language are designed to take advantage of modern Unix facilities to the fullest, and this made porting to Windows a particularly interesting task. This talk covers the story of bringing Swift to Windows from the ground up through an unusual route: cross-compilation on Linux. The talk will cover interesting challenges in porting the Swift compiler, standard library, and core libraries that were overcome in the process of bringing Swift to a platform that challenges the Unix design assumptions.