Apple Internals: Swift in the Kernel

Apple integrates Swift into macOS 27 kernel extensions via KernelKit. Swift runs as an embedded runtime in pthread.kext and Libm.kext within /System/KernelKit. The kernel's core C/C++ components remain unchanged. KernelKit uses a dedicated internal SDK named kernelkit.macosx27.0.internal. Swift code is compiled into separate Xcode targets from libpthread and Libm sources.