If there was, Apple might sue them for it. So far there are GNUStep and Darling but they are not ready for prime time. You can buy an old MacBook for $99 That

If there was, Apple might sue them for it. So far there are GNUStep and Darling but they are not ready for prime time. You can buy an old MacBook for $99 That can run an old MacOSX on it like 10.7 or under but it would only be a Core 2 Duo, but would use Boot camp to run Linux.