It's a Unix system. I know this.
There's a subreddit for everything.
a comparison of the two from 1993.
http://www.opus1.com/www/jms/machten.html
FWIW BeOS made me feel as excited to use a system as IRIX did back when i first used it.
On the "low end", besides Apple's A/UX, Microsoft had Xenix and Commodore had Amiga Unix.