what defines UNIX?
At the end of the day, utilities like GCC, GDB, fortune and X do not define what a UNIX system is - despite that they may come bundled with most UNIXes, so to speak.
GNU do not define UNIX. And neither does your poor and clearly stupid fanaticism for Linux and it's reliance upon Stallman's software (please find me modern Linux-based software that can be easily compiled using a compiler other than gcc).
The only thing, in my mind and I'm sure in the minds of many others, that defines what is a good, compliant UNIX system... is the POSIX standard. After all, MINIX doesn't come with gcc, gdb or X (maybe fortune) - does that mean it's not MINIX? Idiot.
OS X, as far as I know, is POSIX-compliant. That makes you wrong, wrong, wrong, wrong and wrong. I dread to think what you teach at your university.
it's just occured to me that ppp 2.4.0 isn't running /etc/ppp/ip-up - is there something in the docs that I've missed?