Groklaw: The Daemon, the GNU and the Penguin, Ch. 19

“Linus posted his queries, his information and his work on
comp.os.minix beginning in mid-1991. But on 29 January 1992, Andy
Tanenbaum posted a note with the line:

Subject: LINUX is obsolete

“After a few introductory paragraphs, Tanenbaum got to his real
criticism of Linux:

“As a result of my occupation, I think I know a bit about where
operating systems are going in the next decade or so. Two aspects
stand out:

“Microkernel vs Monolithic System…”