"Thus even if you used MINIX 1 when you were in college, try
MINIX 3; you'll be surprised. It is a minimal but functional UNIX
system with X, bash, pdksh, zsh, cc, gcc, perl, python, awk, emacs,
vi, pine, ssh, ftp, the GNU tools and over 400 other programs. It
is all based on a tiny microkernel and is available right now.
"So **PLEASE** no more comments like 'If Tanenbaum thinks
microkernels are so great, why doesn't he write an OS based on
one?' He did. (Actually, one of his students and two of his
programmers did). It is definitely not as complete or mature as
Linux or BSD yet, but it clearly demonstrates that implementing a
reliable, self-healing, multiserver UNIX clone in user space based
on a small, easy-to-understand microkernel is doable..."