From the FAQ:

The short answer is "hardware support". ravynOS should run on most commodity x86_64 hardware using FreeBSD's very stable and performant drivers.

The longer answer is that plus I don't see any real advantage to using xnu. We have merged in Mach support now (big thanks to NetBSD, NextBSD and the iX Systems folks for that) so the xnu approach just seems to add complexity and the effort of writing and maintaining drivers.

Considering how big this project is already, I opted to stick with the BSD kernel - at least for now

Regarding hardware support, will this run on actual Apple silicon? If not, it seems like Linux would have been the better choice for maximizing hardware support, if only for Asahi Linux's work.

(btw, I don't know much about this kind of work, so I have no idea if it's feasible to port the drivers from Asahi to FreeBSD, or if they'll have to start mostly from scratch)

I know nothing about the project apart from the website, but the front page says they aren't a fan of the "ever-closing hardware", so I guess Apple silicon might not be a priority.

> We have merged in Mach support now

Mach the kernel, the IPC system, or the binary format?

Probably because Darwin is half abandoned, while FreeBSD is actively maintained and with plenty of drivers

Darwin is still open sourced, but mainly because of drivers and differences in certain other things (threads maybe, Mach ports / IPC, etc) that don’t have the integration or implementation with existing software is a major headwind to attempting a full encompassing Darwin OS.

PureDarwin was (is?) an attempt that hasn’t been able to break through those headwinds.

Is Darwin used for something other than research? I'd really love to see some homebrew stuff with this kernel.

There's https://www.puredarwin.org/ which is probably great for partial OSX/iOS emulation efforts. That's it as far as I can tell, though.

Possibly driver support. But I would feel better if at some point they co-operate with PureDarwin to run on real XNU.