BSD(i) (plus all its derivates) are not Unix,
GNU is not Unix (that makes nearly 200 Linux Distros not Unix along the way),
Mac OSX is not Unix,
and now -- WOW -- IBM's OS/390, AIX, IRIX, SCO and Solaris are!! What a deal!
IBM's OS/390 is out of the race, AIX & IRIX are "staring at open...