Apple uses bits and pieces of BSD. macOS is not "FreeBSD". Quoting from Mac OS X and iOS Internals by Jonathan Levin: "On top of Mach, but still an inseparable

Apple uses bits and pieces of BSD. macOS is not "FreeBSD". Quoting from Mac OS X and iOS Internals by Jonathan Levin: "On top of Mach, but still an inseparable part of XNU, is the BSD layer. This layer presents a solid and more modern API that provides the POSIX compatibility discussed earlier. The BSD layer provides higher-level abstractions, including, among others: ‰ The UNIX Process model ‰ The POSIX threading model (Pthread) and its related synchronization primitives ‰ UNIX Users and Groups ‰ The Network stack (BSD Socket API) ‰ File system access ‰ Device access (through the /dev directory) XNU’s BSD implementation is largely compatible with FreeBSD’s, but does have some noteworthy changes. After covering Mach, this book turns to BSD, focusing on the implementations of the BSD core, and providing specific detail about the virtual file system switch and the networking stack in dedicated chapters." I don't disagree with Apple providing funding, however the BSD license doesn't require it. Many of the original Windows userland network utilities came directly from BSD, as well.