Originally Posted by wgscott

It is not an analogy. Both Linux and MacOSX (or 11) are unix operating systems. OS X is more closely related to BSD unix, but they are rather more similar than different.

Windows is quite different.

If you want to invoke superficial visual similarities (the windows GUI is based on a variant of the X11 windowing system that Linux uses -- and which, incidently, also works perfectly fine on OS X), feel free, but it is like creating phylogenetics based on organism color rather than DNA sequences.