https://belkadan.com/blog/2020/04/Swift-on-Mac-OS-9/
It uses the MPW emulator, MPW itself, and modified LLVM and Swift libraries. But even within his time constraints (getting it ready for April 1), we've got actual Swift code written and compiled on a modern computer, building to a runnable app on OS 9!
One of these days I'll have to learn Swift, it seems.
Saw this on MacScene: Swift compiled for Mac OS 9!
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