[Tex/LaTex] Is it actually illegal to TeX `texbook.tex`?

copyrightplain-textex-core

At the top of texbook.tex, it is written:

% This manual is copyright (C) 1984 by the American Mathematical Society.
% All rights are reserved!
% The file is distributed only for people to see its examples of TeX input,
% not for use in the preparation of books like The TeXbook.
% Permission for any other use of this file must be obtained in writing
% from the copyright holder and also from the publisher (Addison-Wesley).
\loop\iftrue
  \errmessage{This manual is copyrighted and should not be TeXed}\repeat
\pausing1 \input manmac

Does this actually mean that would be illegal to TeX this file, or is it more likely an attempt at intimidation by Addison-Wesly?

Would it make any difference …

  1. … if the output were only for personal use?

  2. … if the output were only used on-screen, not printed?

  3. … if one already owned a copy of the TeXbook?

(Probably the answers to at least some of these questions vary from country to country.)

Also (this is probably a big can of worms), would it be wrong to do so?

Best Answer

Depending on where you live, I think it can indeed be illegal to process the texbook.tex file into a pdf even for your own private use only.

Not because of copyright law, but because the quoted part of the text represents a license agreement. As you cannot process the document without seeing the warning first as well as actually having to edit the file, you cannot even argue that it is unilateral.

Whether the license agreement is in fact legally binding depends a lot on how your local legal system interprets contract law, but do not assume that just because you do not redistribute, you are automatically in the clear.

Now, is it wrong? That depends on everyone's personal norms and values. For me, I have actually done this, but on the other hand I am currently using my third hardcopy of the TeX Book (having wrecked the first two through heavy use) so I feel entitled now.