- As source was available, Unix evolved fast and diversified.
-> AT&T Unix, BSD (Berkeley Unix), Ultrix (DEC), AIX (IBM), Solaris (Sun), HP-UX (HP), Xenix (Microsoft), etc.
- Andrew Tanenbaum rewrote a Unix kernel for his OS classes for IBM PCs
-> Minix (also Copyrighted)
- Linus Torvalds (as a second year student in 1991) used Minix as a model for a Unix kernel
for Intel 286 CPUs (first Intel CPU with MMU features)
- No Minix code was used. Torvalds chose the GPL (GNU Public License)
|4.1.3. History of Unix: hard times||1. Denx Training Topics||4.1.5. Origin of Free Software|