from what i recall, the kernel is a bsd derivative, under the equivalent license.

as for the file system, i would suspect that beyond the basics needed to get the kernel and initial user space booted, it wil have more in common with mac os of old then unix. that is, dirs that looks like single files in finder, specific dirs where the user can just drop those "app dirs" so that the DE can find them and use them, and so on.

think of it as linux with rox on top...