No, I'm treating OSX as a UNIX. It is advertised as such. I know that you can use the app bundles. But they are only useful for GUI applications. I usually run applications like octave or gnuplot from the terminal or other applications (e.g., Emacs).
It doesn't matter if MacOS is advertised as UNIX or not. Technically, it is UNIX.
The practical issue is that you are using GNU programs written with the Linux/GNU operating system in mind. Of course this experience is sub-par on the Mac, because neither the Octave- nor the Gnuplot-developers see Mac OS X as their primary market.
