Perhaps it's besides the point, but core osx is open source as Darwin and XNU, and I don't see much value in them. NT hybrid kernel is extremely well designed,

Perhaps it's besides the point, but core osx is open source as Darwin and XNU, and I don't see much value in them. NT hybrid kernel is extremely well designed, and there is an ecosystem built around it. It is extremely unlikely anyone at Microsoft will find anything aiding in Office 98 compatability online...