# Re: TeX Licenses & teTeX (Was: Re: forwarded message from Jeff Licquia)

> From: tb@becket.net (Thomas Bushnell, BSG)
> Date: 09 Aug 2002 19:07:26 -0700

>
> In fact, everyone does, in fact, modify TeX before installing it.
> Nobody, in fact, installs an unmodified TeX.  This is a central fact
> massively ignored by so many that I have to say it in each post,
> rather like Cato and Carthage, until you will finally notice it and
> acknowledge its implications.

You are perfectly right. Everyone modifies TeX. However, you cannot
modify it *in any way you want*, and this is a very important point.

Each part of TeX has its own conditions for modificaiton.

1. You cannot edit tex.web, but you can edit the patch file
tex.ch. Even this is not absolutely free: the result must pass trip
test. Note that this is like DFSG: you must pass trip test to be
called TeX, but passing it does not guarantee anything. If trip
test were the *only* requirement, you could easily write a program
cheat.web that would spew correct answers to Knuth's test
regardeless of input, and than say something like "diff cheat.web
tex.web > tex.ch". Presumably this is what Knuth meant by "the
author must be happy with the implementation" -- you cannot be
happy with a cheat.

2. You absolutely cannot modify plain.tex. However, you can preload or
postload a file, which would redefine every command of this file --
including \def itself!

3. You cannot modify cmr10.mf -- but you can make a virtual font that
would load cmr10 in a completely new and strange manner. Or you can

By the way, these ways have parallel in LaTeX world. If you would READ
configuration files (.cfg), that are exact analog of patch files.

The poor C crowd knows only one way of modification: actual editing of
the code. We know dozens in TeX! And that is why we do not *need* to
actually edit the system files.

>
> > To say the truth, it is amusing to see the contortions Thomas must
> > suffer to defense the idea that "TeX is more free than LaTeX". When a
> > copyright notice does not agree with him, he cites Knuth's writings
> > and says that Knuth does not know how to write licenses, but his
> > writings show his intent.
>
> Not at all.  I agree with all the *actual* copyright notices and legal
> permission files on Knuth's actual source.  His own interpretations,
> and those of "the TeX community" are, it seems, wildly at variance
> with the *actual* text of those documents.

Well, earlier you claimed that only LaTeX community is completely
confused and misguided about our licenses. Now you you seem to claim
that both TeX users and Knuth himself do not understand what he
wrote. A rather cheeky notion.

There is an edition of Goethe's memoirs with learned comments. At some
point the old author lists the women he loved and says: "This woman I
loved more than anybody else". The commentator's notes read: "Here
Goethe was wrong".

Actually the *actual* text of documents is pretty simple:

% THIS IS THE OFFICIAL COMPUTER MODERN SOURCE FILE cmr10.mf BY D E KNUTH.
% IT MUST NOT BE MODIFIED IN ANY WAY UNLESS THE FILE NAME IS CHANGED!

% This program is copyright (C) 1982 by D. E. Knuth; all rights are reserved.
% Copying of this file is authorized only if (1) you are D. E. Knuth, or if
% (2) you make absolutely no changes to your copy. (The WEB system provides
% for alterations via an auxiliary file; the master file should stay intact.)
% See Appendix H of the WEB manual for hints on how to install this program.
% And see Appendix A of the TRIP manual for details about how to validate it.
% TeX is a trademark of the American Mathematical Society.

% This is the plain TeX format that's described in The TeXbook.
% N.B.: A version number is defined at the very end of this file;
%       please change that number whenever the file is modified!
% And don't modify the file under any circumstances.

You must have mightly good eyes to see there something "you can modify
there files in any way you want". I must admit my eyes are not as
sharp as this.

> I place preference
> on the actual text of the licenses rather than Knuth's apparent
> misunderstandings of them.

Thomas, may I use this phrase in my collection of quotes for
signatures?

--
Good luck

-Boris

If truth is beauty, how come no one has their hair done in the library?
-- Lily Tomlin