John Lions wrote A Commentary on the UNIX Operating System,
probably the most illegally copied book in computer history. His book,
accompanied by the V6 source code, helped countless number of people
understand and appreciate the ground breaking work done in the Unix
John was a professor at the University of New South Wales, Australia,
when he read Ritchie and Thompson's
Time-Sharing System in May 1974. He encouraged the CS department
to get a license, and at the same they were in the process of
replacing their IBM hardware with CDC Cyber and DEC PDP.
He founded the Australian UNIX systems Users Group, and later started
using Unix to teach his OS classes, for which he created the famous
two slim volumes, one in red cover and one in bright orange,
containing the V6 source code and his line-by-line commentaries.
His books became very popular and he kept receiving overseas orders.
Even Bell Labs ordered the book for their own internal training
courses. Later They assumed the responsibility of distributing the
books, and as V7 came out because of license restriction they stopped
But anxious people made copies and copies and copies... Finally in
1996, with a lot of hard work and follow up by Dennis Ritchie and
Peter Salus and help of Michael Tilson, CIO of SCO (owner of Unix at
the time) The legal issues were resolved and the books were finally
published. Dennis says in his preface to the newly published
"In Lion's commentary, you will see a fresh and questioning
attitude... John clearly admired what he saw, but was quick to point
out its inadequacies..."
Thompson, who as said before does not write much, wrote a paragraph
in the foreword of the book too, which tells us in just a few words
how good a book we're dealing with:
"Finally--one of the most widely distributed underground computer
science documents is freely available. I can still vividly remember
the day in 1977 the first draft of these books came to me by mail.
I took a casual look expecting very little. I ended up reading every
After 20 years, this is still the best exposition of the workings of
a "real" operating system."
John spent three sabbatical periods in Bell Labs as a member of
technical team. His medical condition was failing by the time
the books were published, but he saw the printed version. Joh Lions
died on December 5th, 1998.
An excellent article about John and his books by Rachel Chalmers.
In Memoriam: John Lions
by Peter Salus
Book introduced by the publisher