I built ApplePy because I couldn't find anything that let you use Swift from Python -- only the reverse (embedding Python inside Swift). After experimenting with a few approaches, I got inspired by PyO3's model and decided to build something analogous for the Swift ecosystem.
Why Swift as a native extension language? A few things people underestimate:
- Swift doesn't have a garbage collector. Like Rust, it uses automatic reference counting (implicit by default) with copy-on-write semantics for safe concurrency you get most of Rust's memory safety guarantees with a much lighter syntax.
- Performance lands around 80% of Rust out of the box, with compiler hints available to close the gap further if you need to tune hot paths.
- Swift 6.3 ships native C++ interop, and the same codebase compiles to iOS, Android, Windows, Linux, and macOS.
For Python developers who want native-speed extensions without writing C or wrestling with Rust's learning curve, Swift is a genuinely underappreciated option. ApplePy tries to make that path practical.
The project is early - feedback and contributions very welcome.
