RavynOS is a much more interesting project. Basically it keeps everything that's open-source in Darwin (save for XNU), and re-implements what that's proprietary

RavynOS is a much more interesting project. Basically it keeps everything that's open-source in Darwin (save for XNU), and re-implements what that's proprietary with tailor made free software, on top of a FreeBSD kernel. Since many layers, frameworks and APIs from macOS are reused (even for the GUI which is written in Objective-C and uses the actual Cocoa APIs), the goal is to achieve compatibility with both macOS and FreeBSD apps. And yes, it natively runs Mach-O binaries in the kernel, no emulation layer. "ravynOS is explicitly trying to be compatible with Mac software at a source and eventually a binary level, without losing support for FreeBSD/X11 software, and to implement a very similar experience on the desktop and at the command line. For example, on ravynOS you can type open -a MyApp image.jpg and have image.jpg open in MyApp. You will find things in (mostly) the same directories as a Mac, like ~/Library or /System/Library/Fonts." Most other projects are just vanilla FreeBSD or Linux with a macOS theme.